Double row roller bearing

Abstract

This invention discloses a double-row roller bearing, relating to the field of engineering transmission components. The key technical features include an inner ring, rollers, and first and second clamping rings located on either side of the inner ring's axial direction. Two flanges protrude from the outer circumference of the inner ring, with radially arranged contact surfaces and unloading steps on the inner ring's end face. The vertical surfaces of the unloading steps are parallel to the contact surfaces and recessed inwards towards the flanges. The inner end faces of the first and second clamping rings respectively contact the contact surfaces and cover the outer side of the unloading steps, forming an energy-absorbing cavity together with the step vertical surfaces and bottom surfaces. This invention utilizes the energy-absorbing cavity to provide physical allowance, allowing the flanges to undergo slight elastic deformation under heavy load compression or impact, converting the load into elastic potential energy for absorption and dispersion. This blocks the path of stress transmission to the overrun groove and root, avoiding stress concentration, effectively reducing the risk of fatigue fracture, and improving the bearing's structural strength, toughness, and service life.

Description

Technical Field

[0001] This invention relates to the field of engineering transmission components, and in particular to a double-row roller bearing. Background Technology

[0002] Double-row roller bearings are widely used in the spindle support systems of various mechanical equipment. In existing double-row roller bearing assembly structures, a clamping ring is commonly used to press the inner ring against the axial end face for axial positioning. The end face of the clamping ring that mates with the inner ring is machined into a flat, complete reference surface, forming a large-area rigid contact with the outer end face of the inner ring. Simultaneously, the working surface of the inner ring is provided with a retaining flange for axially limiting the rollers, and the bottom of the retaining flange has a runout groove for machining tool retraction.

[0003] Under continuous operation, the spindle system inevitably experiences slight flexural deformation due to alternating heavy loads, temperature cycles, and progressive wear of mating components. This flexural deformation causes the rollers inside the double-row roller bearing to deviate from their ideal trajectory, resulting in slight tilting. When the rollers are tilted, an off-center load contact occurs between the roller end face and the inner ring flange. In existing flat clamp ring assembly structures, the clamp ring plane is directly supported behind the inner ring flange, giving the inner ring flange excessively high structural support stiffness. This excessive structural support stiffness causes localized excessive contact stress concentration when the inner ring flange is subjected to off-center load compression from the roller end face, which is then transferred to the root of the inner ring flange and the overrun groove area. Stress concentration easily leads to micro-fatigue spalling and abnormal wear at the root of the inner ring flange, reducing the service life of the double-row roller bearing. Summary of the Invention

[0004] The purpose of this invention is to provide a double-row roller bearing that has the advantages of effectively unloading edge concentrated stress, accurately attenuating high-frequency vibration, high operational stability under alternating heavy load conditions, and long overall service life.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A double-row roller bearing includes an inner ring, rollers, a first clamping ring, and a second clamping ring; Two flanges are provided protruding on the outer circumferential surface of the inner ring. Each flange has an inner flange side facing the roller and an outer flange side facing the corresponding side clamping ring. The junction of the inner side surface of the retaining edge and the outer circumferential surface of the inner ring is recessed into the retaining edge to form a runout groove. The inner end face of the first clamping ring and the inner end face of the second clamping ring are respectively arranged on the outer side of the two flanges on both sides of the inner ring axial direction. The feature is that the outer side of the retaining edge is provided with a contact reference surface located on the radial inner side and an inner ring end face unloading step located on the radial outer side. The inner ring end face unloading step has a step elevation parallel to the mating reference surface and a step bottom surface perpendicular to the mating reference surface. The stepped surface is recessed towards the inside of the retaining edge relative to the mating reference surface; The inner end face of the first clamping ring and the inner end face of the second clamping ring respectively contact and adhere to the fitting reference surface on the outer side surface of the two side guards; The inner end face of the first clamping ring and the inner end face of the second clamping ring respectively cover the outer side of the unloading step of the inner ring end face of the two side guards. The inner end face of the first clamping ring and the inner end face of the second clamping ring are respectively enclosed by the step elevation of the unloading step of the inner ring end face on the corresponding side and the step bottom surface of the unloading step of the inner ring end face on the corresponding side, forming energy-absorbing cavities on both sides of the inner ring in the axial direction.

[0006] Further configuration: The overtravel groove is an arc-shaped groove, and the lowest point of the arc of the overtravel groove is located at the innermost radial root of the sidewall; the bottom surface of the unloading step on the inner ring end face is located radially outside the lowest point of the arc of the overtravel groove. The inner side of the retaining edge has an inclination angle from the inside out, with the inclination angle value being 10'-30'.

[0007] Further configuration: the two flanges of the inner ring define an area for accommodating the roller; the outer circumferential surface of the inner ring within the area forms an inner ring raceway surface that fits against the roller; the radial height of the inner ring raceway surface is the same as the radial height of the bottom surface of the unloading step on the end face of the inner ring.

[0008] Further configuration: the axial vertical distance between the step elevation of the inner ring end face unloading step and the plane where the contact reference surface is located is the axial depth of the energy absorption cavity; the overall thickness of the flange along the axial direction of the double-row roller bearing is the total axial thickness of the flange; the axial depth of the energy absorption cavity is 1 / 5 to 1 / 3 of the total axial thickness of the flange.

[0009] Further features include: a retainer seat, which is divided into an upper retainer half-ring and a lower retainer half-ring by a horizontal split plane; A retainer end cap is located in the axial position of the retainer seat and is used to clamp the roller between the retainer end cap and the retainer seat. Multiple tungsten alloy counterweight columns are divided into a first counterweight array and a second counterweight array. The first counterweight array is arranged in the upper half of the retainer semi-ring, and the second counterweight array is arranged in the lower half of the retainer semi-ring. The outer circumference of each tungsten alloy counterweight column is threaded, and the tungsten alloy counterweight column is connected to the retainer end cap and the retainer seat through the thread.

[0010] Further configuration: Both the first and second counterweight arrays contain two tungsten alloy counterweight columns. In the upper half of the retainer semi-ring, the two tungsten alloy counterweight columns are symmetrically arranged on both sides of the midpoint of the circumference of the upper half of the retainer semi-ring; in the lower half of the retainer semi-ring, the two tungsten alloy counterweight columns are symmetrically arranged on both sides of the midpoint of the circumference of the lower half of the retainer semi-ring.

[0011] Further configuration: Multiple windows for accommodating rollers are arranged at intervals along the circumferential direction on the outer circumferential surface of both the upper half of the retainer semi-ring and the lower half of the retainer semi-ring, and a solid metal beam is formed between adjacent windows; a cylindrical hole is opened in the solid metal beam along the axial direction of the retainer seat, and a tungsten alloy counterweight column is installed in the cylindrical hole.

[0012] Further configuration: The retainer base has an even number of windows; these even number of windows are divided into two equal groups, respectively arranged in the upper half of the retainer semi-ring and the lower half of the retainer semi-ring; the windows in the upper half of the retainer semi-ring are evenly and equidistantly distributed along the circumference, and the included angle between adjacent windows and between adjacent solid metal beams is a fixed division angle; the windows in the lower half of the retainer semi-ring are evenly and equidistantly distributed along the circumference, and the included angle between adjacent windows and between adjacent solid metal beams is also the fixed division angle; the two tungsten... The alloy counterweight columns are respectively installed in two solid metal beams on both sides of the window opening located at the midpoint of the circumference of the upper half of the retainer semi-ring. The angle formed by the center lines of the two tungsten alloy counterweight columns in the upper half of the retainer semi-ring and the center of the retainer seat is equal to the fixed graduation angle. The two tungsten alloy counterweight columns in the lower half of the retainer semi-ring are respectively installed in two solid metal beams on both sides of the window opening located at the midpoint of the circumference of the lower half of the retainer semi-ring. The angle formed by the center lines of the two tungsten alloy counterweight columns in the lower half of the retainer semi-ring and the center of the retainer seat is also equal to the fixed graduation angle.

[0013] Further configuration: The upper half retainer half ring and the lower half retainer half ring are provided with corresponding internal positioning pin holes at both ends of the joint interface. An internal positioning pin is inserted into the internal positioning pin hole. The internal positioning pin spans the joint interface and is used to limit the relative misalignment between the upper half retainer half ring and the lower half retainer half ring.

[0014] Further features include an outer ring and a second outer ring; a main positioning hole is provided in the lateral engagement end faces of the outer ring and the second outer ring; a main positioning pin and an anti-detachment pin are assembled between the lateral engagement end faces of the outer ring and the second outer ring; the main positioning pin is assembled inside the main positioning hole; an anti-detachment pin hole is provided on the side of the main positioning pin, penetrating its main body, and the anti-detachment pin is inserted into the anti-detachment pin hole.

[0015] In summary, the present invention has the following beneficial effects: First, in this invention, by providing an inner ring end face unloading step on the radially outer side of the outer side of the retaining edge, the step vertical surface parallel to the fitting reference surface is recessed towards the inside of the retaining edge relative to the fitting reference surface. The inner end face of the first clamping ring and the inner end face of the second clamping ring respectively contact and fit with the fitting reference surface on the outer side of the two retaining edges, so as to cover the outer side of the inner ring end face unloading step of the two retaining edges respectively. Finally, the inner end face of the first clamping ring and the inner end face of the second clamping ring respectively enclose the step vertical surface of the inner ring end face unloading step on the corresponding side and the step bottom surface of the inner ring end face unloading step on the corresponding side, forming energy-absorbing cavities on both sides of the inner ring in the axial direction. When the rollers are under load and apply alternating eccentric loads to the inner side of the flange, the flange undergoes elastic displacement deformation axially outward, relying on the space volume provided by the energy-absorbing cavity on the back of the unloading step on the inner ring end face. In the double-row roller bearing operating under continuous lubrication, the energy-absorbing cavity is filled with lubricating medium. The high-frequency alternating elastic displacement deformation of the flange alternatingly compresses the lubricating medium inside the energy-absorbing cavity, forming a micro-compression oil film damping effect within the space enclosed by the inner end face of the first and second clamping rings and the unloading step on the inner ring end face corresponding to either the first or second clamping ring. This compression oil film damping effect converts the rigid impact load transmitted by the rollers into heat energy through fluid viscous friction, which is then carried away by the lubricating medium, thus substantially dissipating the impact kinetic energy. The unloading step on the inner ring end face, combined with the compression oil film damping effect, jointly blocks the path of alternating stress transmission to the overrun groove and the innermost radial root position of the flange.

[0016] Secondly, in this invention, the lowest point of the arc of the overrun groove is located at the innermost radial root of the flange, and the bottom surface of the unloading step on the inner ring end face is located radially outside the lowest point of the arc of the overrun groove. This causes the bending fulcrum where the flange cantilever structure elastically yields under stress to shift radially outward, effectively avoiding the lowest point of the overrun groove which has a material notch effect. Furthermore, the 10'-30' micro-inclination surface provides geometric tolerance space for the dynamic deflection of the roller end face under heavy load. When subjected to alternating heavy loads, the outward elastic yielding deformation of the flange body... The stress is mainly concentrated in the radial region above the bottom of the step, making it difficult for the tensile stress to be transmitted and diffused to the bottom overrun groove area. At the same time, the inclined inner side of the flange can adapt to the bending deformation posture of the roller under stress, transforming the sharp angle interference between the roller end face and the flange into a smooth and seamless regional surface contact. This reduces the probability of fatigue tearing at the root of the overrun groove due to structural deformation coupling, optimizes the contact stress distribution model between the roller and the flange under off-center load conditions, and further improves the load limit and operational reliability of the double-row roller bearing.

[0017] Third, to reassemble the upper and lower retainer half-rings, the retainer seat must be equipped with fastening connecting components. These connecting components result in a structural mass surplus in the horizontal axis of the retainer seat at the horizontal parting plane. Under rotational conditions, this mass surplus causes the retainer seat's dynamic center of mass to deviate from its rotational geometric center, generating centrifugal excitation forces. By installing tungsten alloy counterweights within cylindrical holes in solid metal beams located adjacent to the midpoints of the upper and lower retainer half-rings, a local mass compensation torque can be generated in the axis orthogonal to the horizontal parting plane. When the retainer seat rotates, the centrifugal inertia generated by the tungsten alloy counterweights installed in the first and second counterweight arrays balances the additional centrifugal inertia caused by the connecting components at the horizontal parting plane. The tungsten alloy counterweights guide the retainer seat's dynamic center of mass toward its rotational geometric center, improving the retainer seat's rotational stability under rotational conditions.

[0018] Fourth, by creating corresponding internal locating pin holes at both ends of the mating interface between the upper and lower retainer half-rings, and inserting built-in locating pins that bridge the mating interface into these holes, the rigid shear resistance provided by the built-in locating pins within the mating interface achieves a physical constraint on the radial and axial displacement tendencies between the upper and lower retainer half-rings without increasing the external structural dimensions of the retainer. The bridging structure of the built-in locating pins restricts relative misalignment at the mating interface, maintaining the structural integrity and assembly alignment accuracy of the retainer during operation, reducing roller interference and abnormal wear caused by misalignment steps, and improving the overall operational stability and guiding reliability of the split retainer.

[0019] Fifth, the split outer rings require extremely high alignment precision at the joint. The main locating pin bridges between the outer ring and the second outer ring, providing a stable positioning reference. Meanwhile, the anti-detachment pin is inserted into the lateral anti-detachment pin hole of the main locating pin, rigidly locking the main locating pin in the interface. This design of perpendicularly intersecting pins not only effectively prevents accidental detachment of the positioning components but also significantly improves the assembly reliability and overall positioning accuracy of the split outer rings without adding complex connecting parts. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of a double-row roller bearing; Figure 2 yes Figure 1 AA section view in the middle; Figure 3 This is a schematic diagram of the inner ring structure; Figure 4 yes Figure 3 Enlarged view of point B; Figure 5 This is a schematic diagram of the structure of the retainer; Figure 6 This is a schematic diagram showing the connection between the base and the tungsten alloy counterweight column; Figure 7 This is a cross-sectional view of the assembly with built-in locating pins at the interface of the retainer seat. Figure 8 This is a side view of the retainer end cap; Figure 9 This is a top view of the retainer end cap; Figure 10 This is a schematic diagram of the microstructure of the root of the retaining wall in Comparative Example 1; Figure 11 This is a schematic diagram of the microstructure of the root of the retaining wall in Comparative Example 2; Figure 12 This is a schematic diagram of the microstructure of the root of the retaining edge in Example 1.

[0021] In the diagram, 01 represents the outer ring; 02. Inner ring; 021. Side flange; 021a. Inner side of side flange; 021b. Outer side of side flange; 022. Overrun groove; 023. Inner ring raceway surface; 03. Roller; 101. Unloading step on inner ring end face; 101a. Fitting reference surface; 102. Energy absorption cavity; 104. Step elevation; 105. Step bottom surface; 04. Retainer seat; 04-1. Upper half of the retainer semi-ring; 04-2. Lower half of the retainer semi-ring; 405. Internal locating pin hole; 406. Built-in locating pin; 21. Second outer ring; 56. Main locating pin; 56-1. Anti-detachment pin; 96. First clamping ring; 96-1. Second clamping ring; 41. Retainer end cap; 400. Tungsten alloy counterweight column; 401. Window opening; 402. Solid metal beam; 403. Cylindrical hole. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] A type of double-row roller bearing, such as Figure 1 and Figure 2 As shown, it includes an inner ring 02, a roller 03, a first clamping ring 96, and a second clamping ring 96-1. The roller 03 is arranged around the inner ring 02, and the first clamping ring 96 and the second clamping ring 96-1 are respectively arranged on both sides of the axial direction of the inner ring 02.

[0025] like Figure 1 As shown, the external structure of the double-row roller bearing includes an outer ring 01 and a second outer ring 21. The outer ring 01 is arranged around the periphery of the first row of rollers 03, and the second outer ring 21 is arranged around the periphery of the second row of rollers 03. The outer ring 01 and the second outer ring 21 are arranged adjacent to each other along the axial direction of the double-row roller bearing. The outer ring 01 has a rearward-facing lateral engagement end face, and the second outer ring 21 has a forward-facing lateral engagement end face. The lateral engagement end faces of the outer ring 01 and the second outer ring 21 are arranged facing each other and mating.

[0026] The outer ring 01 and the second outer ring 21 share a main positioning hole on their lateral engagement end faces. The positioning system of the outer ring assembly includes a rigid main positioning pin 56 and an anti-disengagement pin 56-1. The main positioning pin 56 is integrally assembled inside the main positioning hole, and its outer circumferential surface is tightly fitted with the outer ring 01 and the second outer ring 21, limiting the relative misalignment between the outer ring 01 and the second outer ring 21.

[0027] To prevent radial movement of the main locating pin 56 during assembly or operation, a laterally penetrating anti-detachment hole is machined on the main locating pin 56 body. The anti-detachment pin 56-1 is inserted into the anti-detachment hole in a direction perpendicular to the axis of the main locating pin 56. The outer diameter of the main locating pin 56 can be set to 25 mm, and the diameter of its internal anti-detachment hole is 8 mm. The anti-detachment pin 56-1 passes through the mounting interface of the outer ring and through the 8 mm anti-detachment hole, thereby fixing the main locating pin 56 in the set position.

[0028] like Figure 3 and Figure 4As shown, two flanges 021 are radially protruding outward on the outer circumferential surface of the inner ring 02. Each flange 021 has an inner flange surface 021a facing the inner roller 03 on both axial sides, and an outer flange surface 021b facing away from the roller 03 and towards the corresponding side clamping ring. At the junction of the inner flange surface 021a and the outer circumferential surface of the inner ring 02, the material is recessed towards the solid interior of the flange 021, thereby forming a runout groove 022. The inner end face of the first clamping ring 96 and the inner end face of the second clamping ring 96-1 are respectively arranged at the outer flange surface 021b of the two flanges 021 on both axial sides of the inner ring 02.

[0029] The outer surface 021b of the retaining edge is divided into two regions radially, including the inner contact reference surface 101a and the outer inner ring end face unloading step 101. The geometry of the inner ring end face unloading step 101 includes a step elevation 104 and a step bottom surface 105, wherein the plane containing the step elevation 104 is parallel to the contact reference surface 101a, the plane containing the step bottom surface 105 is perpendicular to the contact reference surface 101a, and the step elevation 104 is further recessed towards the inside of the retaining edge 021 relative to the contact reference surface 101a.

[0030] The inner end faces of the first clamping ring 96 and the second clamping ring 96-1 are respectively in axial surface contact with the contact reference surface 101a on the outer side surface 021b of the two side guards. At this time, the inner end faces of the first clamping ring 96 and the second clamping ring 96-1 respectively cover the outer side of the unloading step 101 of the inner ring end face of the two side guards 021 on the outer side of the axial direction. Through the above assembly, the inner end faces of the first clamping ring 96 and the second clamping ring 96-1 are respectively enclosed by the step vertical surface 104 and the step bottom surface 105 of the unloading step 101 of the inner ring end face on the corresponding side, thereby forming closed energy-absorbing cavities 102 on both sides of the inner ring 02.

[0031] In this embodiment, during machining, the fitting reference surface 101a on the outer side surface 021b of the inner ring 02 is used as the positioning starting point. A turning tool is used to cut 0.5 mm to 1.5 mm into the interior of the flange 021 along the axial direction to form a stepped surface 104, and a vertically intersecting step bottom surface 105 is formed by cutting along the radial direction. The specific depth of the stepped surface 104 recessed relative to the fitting reference surface 101a is determined by precisely controlling the feed rate, thereby providing a precise volume boundary for the subsequent enclosing with the clamping ring to form the energy-absorbing cavity 102.

[0032] In this embodiment, the overtravel groove 022 is an arc-shaped groove, which is recessed downwards and has a lowest arc point. The lowest arc point of the overtravel groove 022 is located at the innermost radial root of the retaining edge 021. At the same time, the unloading step 101 of the inner ring end face has a step bottom surface 105. In terms of radial height arrangement, the step bottom surface 105 is located radially outside the lowest arc point of the overtravel groove 022. The step bottom surface 105 of the unloading step 101 of the inner ring end face and the lowest arc point of the overtravel groove 022 form a spatially staggered relationship in the radial direction.

[0033] In addition, the inner ring 02 also includes an inner side surface 021a of the flange and an inner ring raceway surface 023. The inner side surface 021a of the flange has an inclination angle that deviates from the inner ring raceway surface 023 toward the axially outer side of the inner ring 02, and the numerical range of the inclination angle is set to 10' to 30', preferably 20'.

[0034] When actually machining the flange 021, the horizontal reference plane where the inner raceway surface 023 is located can be used as the 0-degree reference. By controlling the deflection feed trajectory of the CNC lathe cutting tool, a small inclined surface that tilts outward on the inner side of the flange 021 is machined. The value of the inclination angle is precisely set and machined to 20', so that the inner side surface 021a of the flange presents a microscopic outward tilt shape.

[0035] In this embodiment, a physical area for accommodating the roller 03 is defined axially between the two flanges 021 of the inner ring 02. The outer circumferential surface of the inner ring 02 within this area forms an inner ring raceway surface 023 that directly contacts the outer surface of the roller 03. The radial height of the inner ring raceway surface 023 is the same as the radial height of the bottom surface 105 of the unloading step 101 on the inner ring end face, and they are flush on the same radial horizontal plane.

[0036] Furthermore, there is an axial vertical distance between the step elevation 104 of the unloading step 101 on the inner ring end face and the plane containing the contact reference surface 101a, which is the axial depth of the energy-absorbing cavity 102. Simultaneously, the overall thickness of the flange 021 along the axial direction of the double-row roller bearing is the total axial thickness of the flange. In terms of spatial proportions, the axial depth of the energy-absorbing cavity 102 is 1 / 5 to 1 / 3 of the total axial thickness of the flange.

[0037] When machining the inner ring 02 of a double-row roller bearing, if the overall thickness of the flange 021 along the axial direction of the double-row roller bearing is set to 15 mm, then when turning the outer side 021b of the flange to form the unloading step 101 on the end face of the inner ring, the depth of cut is controlled so that the axial vertical distance between the plane of the step surface 104 and the plane of the mating reference surface 101a is within the range of 3 mm to 5 mm, so that the axial depth of the energy-absorbing cavity 102 falls precisely within the range of 1 / 5 to 1 / 3 of the total axial thickness of the flange.

[0038] like Figure 5 and Figure 6 As shown, the internal structure of the double-row roller bearing also includes a cage housing 04 and multiple tungsten alloy counterweight columns 400. The cage housing 04 is divided into an upper cage half-ring 04-1 and a lower cage half-ring 04-2 by a horizontally split surface. The multiple tungsten alloy counterweight columns 400 are divided into a first counterweight array and a second counterweight array. The first counterweight array is arranged in the upper cage half-ring 04-1, and the second counterweight array is arranged in the lower cage half-ring 04-2.

[0039] Both the outer circumferential surface of the upper retainer semi-ring 04-1 and the outer circumferential surface of the lower retainer semi-ring 04-2 are provided with multiple windows 401 for accommodating rollers arranged at intervals along the circumferential direction. Solid material is retained between adjacent windows 401 to form a solid metal beam 402. A total of 34 windows 401 are arranged on the retainer seat 04. These 34 windows 401 are divided into two groups, with 17 windows 401 arranged in the upper retainer semi-ring 04-1 and the other 17 windows 401 arranged in the lower retainer semi-ring 04-2.

[0040] Within the upper retainer semi-ring 04-1, the angle between the centerlines of the two windows 401 located at the extreme ends of the circumference and the center of the retainer seat 04 is 164°. Since the 17 windows 401 are evenly distributed within this 164° arc, the angle between adjacent windows 401 and between adjacent solid metal beams 402 is 10.25°. Within the lower retainer semi-ring 04-2, the angle between the centerlines of the two windows 401 located at the extreme ends of the circumference and the center of the retainer seat 04 is also 164°.

[0041] Both the first and second counterweight arrays contain two tungsten alloy counterweight columns 400. A cylindrical hole 403 is formed within a specific solid metal beam 402 along the axial direction of the retainer seat 04, and the tungsten alloy counterweight columns 400 are physically installed within the cylindrical hole 403. Within the upper retainer semi-ring 04-1, the two tungsten alloy counterweight columns 400 are symmetrically arranged on either side of the midpoint of the circumference of the upper retainer semi-ring 04-1. Specifically, these two tungsten alloy counterweight columns 400 are respectively installed within two adjacent solid metal beams 402 on either side of the window 401 located immediately adjacent to the center of the circumference. Based on the aforementioned geometric spacing of the window arrangement, the angle formed between the centerline of these two tungsten alloy counterweight columns 400 within the upper retainer semi-ring 04-1 and the center of the retainer seat 04 is naturally 10.25°. Inside the lower half of the retainer semi-ring 04-2, two tungsten alloy counterweight columns 400 are also symmetrically arranged on both sides of the midpoint of the circumference of the lower half of the retainer semi-ring 04-2, and the angle formed by the center line and the center of the retainer seat 04 is 10.25°.

[0042] In this embodiment: When machining the retainer seat 04 on a CNC machine tool, 17 window holes 401 are first milled evenly within a span of 164° using a fixed indexing angle of 10.25°, thereby naturally forming multiple solid metal beams 402 with the same 10.25° interval. When dynamic balancing counterweights need to be implanted, the equipment is positioned at the window hole 401 in the middle of the upper half of the retainer semi-ring 04-1. Two solid metal beams 402 adjacent to the left and right sides of the central window hole 401 are selected, and cylindrical holes 403 are drilled axially and tungsten alloy counterweight columns 400 are installed. In this way, the included angle of the two tungsten alloy counterweight columns is naturally the cutting indexing angle of 10.25° of the machine tool, achieving a highly precise symmetrical arrangement without recalibrating the reference.

[0043] like Figure 7 As shown, a mating interface is formed between the upper half of the retainer half ring 04-1 and the lower half of the retainer half ring 04-2 of the retainer seat 04. Corresponding internal locating pin holes 405 are provided at both ends of the mating interface in the circumferential direction.

[0044] An internal locating pin 406 is inserted into the internal locating pin hole 405. The internal locating pin 406 spans the mating interface. The internal locating pin 406 is located between the upper half-ring 04-1 and the lower half-ring 04-2 of the retainer, with its axial ends extending into the corresponding internal locating pin holes 405. The outer circumferential surface of the internal locating pin 406 is in contact with the inner wall of the internal locating pin hole 405.

[0045] When the retainer seat 04 is in the semi-finished product processing stage, a blind hole with a diameter of 6 mm is drilled at the two ends of the circumference of the mating interface, shifted radially inward by 5 mm, to serve as an internal locating pin hole 405. During bearing assembly, the built-in locating pin 406 is first installed into the internal locating pin hole 405 on the lower half of the retainer half ring 04-2, with 8 mm of the pin shaft exposed axially upward. Then, the upper half of the retainer half ring 04-1 is aligned and engaged with the exposed part of the built-in locating pin 406 through its corresponding internal locating pin hole 405, so that the built-in locating pin 406 is completely concealed within the solid material of the mating interface.

[0046] like Figure 8 and Figure 9 As shown, the double-row roller bearing also includes a cage end cap 41, which is disposed at an axial position on the cage seat 04. The roller 03 is located between the cage end cap 41 and the cage seat 04.

[0047] The outer circumference of the tungsten alloy counterweight column 400 is threaded. The retainer end cap 41 is fixed to the retainer seat 04 via the threaded connection on the tungsten alloy counterweight column 400.

[0048] During the assembly of the retainer assembly, the roller 03 is first placed inside the window 401 of the retainer seat 04, and then the retainer end cap 41 is axially placed over the end face of the retainer seat 04. Four tungsten alloy counterweights 400 with standard threads on their outer circumference and a material density of 18 g / cm³ are selected, and passed through the pre-set cylindrical holes 403 on the retainer end cap 41 and screwed into the cylindrical holes 403 inside the retainer seat 04. By tightening the tungsten alloy counterweights 400, a rigid connection is achieved between the retainer end cap 41 and the retainer seat 04, and dynamic balance mass compensation for the overall retainer structure is completed simultaneously.

[0049] To achieve the aforementioned mechanical properties of the double-row roller bearing under alternating heavy load conditions, in this embodiment, the inner ring 02, outer ring 01, second outer ring 21, and roller 03 are all forged from high-carbon chromium bearing steel and subjected to quenching and tempering treatment to provide basic structural compressive stiffness and material yield strength that allows for micro-elastic displacement. Furthermore, the outer circumferential surface of the main locating pin 56 is assembled with the inner wall surface of the main locating hole using a micro-interference fit, thereby ensuring that under alternating forces, the main locating pin 56 can provide high structural stiffness and anti-deflection positioning accuracy for the two adjacent outer rings.

[0050] The following embodiments and comparative examples are set up by adopting the above-described implementation methods. Example 1

[0051] A double-row roller bearing has a structure completely consistent with the above-described embodiment. Key parameters are set as follows: the axial depth of the energy-absorbing cavity 102 is 1 / 4 of the total axial thickness of the flange; the inclination angle of the inner side surface 021a of the flange towards the outer side is 20'; the outer ring assembly includes a main locating pin 56 and an anti-loosening pin 56-1 arranged in a cross-locking layout; the retainer seat 04 includes tungsten alloy counterweight columns 400 symmetrically distributed at an included angle of 10.25°. Example 2

[0052] A double-row roller bearing has the same basic structure as Embodiment 1, except that the key parameters are set to lower limits: the axial depth of the energy-absorbing cavity 102 is 1 / 5 of the total axial thickness of the flange; the inclination angle of the inner side surface 021a of the flange to the outer side is 10'. Example 3

[0053] A double-row roller bearing has the same basic structure as Embodiment 1, except that the key parameters are set to upper limits: the axial depth of the energy-absorbing cavity 102 is 1 / 3 of the total axial thickness of the flange; the inclination angle of the inner side surface 021a of the flange to the outer side is 30'.

[0054] Comparative Example 1; A double-row roller bearing adopts a conventional structure: the flange is a solid structure with no unloading steps or energy-absorbing cavities; the inner side of the flange has an inclination angle of 0'; the outer ring assembly is positioned by a rigid cylindrical pin in only one direction; and the retainer housing has no tungsten alloy counterweight column.

[0055] Comparative Example 2; A double-row roller bearing has the same basic structure as Embodiment 1, except that the axial depth of the energy-absorbing cavity 102 is only 1 / 10 of the total axial thickness of the flange.

[0056] Comparative Example 3: A double-row roller bearing, the basic structure of which is the same as that of Example 1, except that the inclination angle of the inner side of the flange is 0'.

[0057] Comparative Example 4: A double-row roller bearing, whose basic structure is the same as that of Example 1, except that: the outer ring assembly retains only the circumferential main locating pin 56, and the cross locking structure of the anti-loosening pin 56-1 is cancelled, and positioning is achieved by relying on a single straight pin.

[0058] Performance testing; Samples from Examples 1-3 and Comparative Examples 1-4 were installed on an M-2000 heavy-duty rolling mill neck fatigue testing rig. Test parameters were set as follows: constant radial load of 5000 kN, axial eccentric load of 800 kN, spindle speed of 120 r / min, and lubricating oil supply pressure of 0.5 MPa. Continuous operation was conducted. All data during operation were recorded. The fatigue life test continued until irreversible bearing failure, such as fracture or severe spalling, with an upper limit set at 15,000 hours.

[0059] Experimental results data; Summary Table 1 of the performance test results of double-row roller bearings;

[0060] Combining the test data from Examples 1-3 and Comparative Example 1, it can be seen that the embodiments employing the technical solution of this invention outperform Comparative Example 1, which uses a traditional structure, in terms of peak vibration acceleration, lubricant leakage rate, maximum tensile stress at the root of the overrun groove, and overall fatigue life. This demonstrates that the unloading step and energy-absorbing cavity on the inner ring end face, the inclination angle of the inner side of the flange, the radially spaced main locating pins and anti-detachment pins between the outer ring mating surfaces, and the tungsten alloy counterweight columns symmetrically arranged at a specific angle within the bearing housing can produce an effective synergistic effect, significantly improving the operational stability and service life of double-row roller bearings under alternating heavy load conditions.

[0061] Combining Examples 1-3 with Comparative Example 2 and referring to Table 1, it can be seen that when the depth of the energy-absorbing cavity deviates from the lower limit of the numerical range, such as 1 / 10 in Comparative Example 2, the maximum tensile stress at the root of the overrun groove significantly increases from 185 MPa in Example 1 to 420 MPa, resulting in a shortened fatigue life of 6800 hours and cracking failure. This data comparison shows that the parameter range of 1 / 5 to 1 / 3 of the present invention can provide sufficient and appropriate elastic displacement margin for the retaining edge, which is the key structural parameter range for achieving effective unloading of concentrated stress.

[0062] Combining Example 1 and Comparative Example 3 with Table 1, it can be seen that in Comparative Example 3, the inclination angle is 0' when the inner side of the retaining edge is not set. Although an energy-absorbing cavity is set inside, the rollers undergo micro-deflection under heavy load and directly interfere with the vertical inner side of the retaining edge, causing the peak vibration acceleration to rise to 3.8 m / s², and surface peeling occurs after 8500 hours. This indicates that the inclination angle of the inner side of the retaining edge, which is axially inclined outward from the inner ring raceway towards the inner ring, plays an irreplaceable role in guiding the dynamic fit of the rollers. Combined with the unloading step on the inner ring end face, it optimizes the frictional stress state of the contact surface.

[0063] Combining Example 1 and Comparative Example 4 with Table 1, it can be seen that after the cross-locking structure of the anti-detachment pin is removed from the outer ring assembly, relying solely on a single straight pin for positioning, the bearing is prone to radial slippage and force displacement under complex vibrations. This causes the peak vibration acceleration to rise sharply from 2.1 m / s² in Example 1 to 6.7 m / s², ultimately leading to shearing of the single straight pin after 9200 hours. This demonstrates the effectiveness of the vertical cross-layout of the main positioning pin and the anti-detachment pin. The anti-detachment pin rigidly locks the main positioning pin in the interface, effectively preventing accidental movement or detachment of the positioning components and protecting the positioning accuracy and structural integrity of the mating surface.

[0064] like Figure 10 , Figure 11 , Figure 12 The image shown is a metallographic micrograph of the material at the root of the inner ring retaining edge after the experimental test.

[0065] like Figure 10 As shown, in the metallographic section at the root of the solid retaining edge in Comparative Example 1, extreme stress concentration was observed because the outer side of the retaining edge was completely filled with solid metal, leaving no room for retreat. After alternating heavy-load extrusion, severe plastic elongation and slippage occurred at the grain boundaries, and clear, penetrating fatigue microcracks extending deep into the internal solid surface were initiated at the lowest point of the arc of the runout groove. This tearing of the underlying grain boundaries ultimately led to macroscopic fracture in Comparative Example 1 after 4500 hours.

[0066] like Figure 11As shown in the metallographic cross-section of Comparative Example 2, although an inner ring end face unloading step and an energy-absorbing cavity are provided on the outer side of the retaining edge, the axial depth of the energy-absorbing cavity is only 1 / 10 of the total axial thickness of the retaining edge, deviating from the lower limit of the parameters defined in this invention. The metallographic structure shows that the shallow cavity fails to provide sufficient physical allowance, and the concentrated stress cannot be completely unloaded and dissipated. The material interior is still densely covered with dark localized stress accumulation patches and microscopic pitting corrosion features. These microscopic stress damage areas are very likely to evolve into fatigue sources under long-term alternating loads, confirming the test result that its lifespan can only reach 6800 hours.

[0067] like Figure 12 As shown in the metallographic cross-section of Example 1, since the axial depth of the energy-absorbing cavity is 1 / 4 of the total axial thickness of the retaining edge, a macroscopic elastic clearance space is provided for the root of retaining edge 021. The metal flow lines smoothly shift upwards towards the unloading step on the inner end face, successfully avoiding the lowest point of the overrun groove. The metallographic diagram further confirms that the metal grains in this region maintain a completely healthy equiaxed shape, with a dense and smooth structure, without any grain boundary slip or dark stress accumulation patches. The surface of the overrun groove in Example 1 is smooth, with no signs of fatigue microcrack initiation, physically confirming the role of the energy-absorbing cavity size parameters defined in this invention in resisting fatigue fracture.

[0068] The above embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A double-row roller bearing, comprising an inner ring (02), rollers (03), a first clamping ring (96) and a second clamping ring (96-1); Two ribs (021) are protrudedly arranged on the outer circumferential surface of the inner ring (02), each rib (021) has a rib inner side surface (021a) facing the rollers (03) and a rib outer side surface (021b) facing the corresponding side clamping ring; The intersection of the rib inner side surface (021a) and the outer circumferential surface of the inner ring (02) is recessed inwardly of the rib (021), forming an overrun groove (022); The inner end surface of the first clamping ring (96) and the inner end surface of the second clamping ring (96-1) are arranged at the rib outer side surface (021b) of the two ribs (021) on the two axial sides of the inner ring (02) respectively; characterized in that The rib outer side surface (021b) is provided with a fitting reference surface (101a) on the radially inner side and an inner ring end surface unloading step (101) on the radially outer side in the radial direction; The inner ring end surface unloading step (101) has a step vertical surface (104) parallel to the fitting reference surface (101a) and a step bottom surface (105) perpendicular to the fitting reference surface (101a); The step vertical surface (104) is recessed inwardly of the rib (021) relative to the fitting reference surface (101a); The inner end surface of the first clamping ring (96) and the inner end surface of the second clamping ring (96-1) are respectively in surface contact with the fitting reference surface (101a) on the two side rib outer side surfaces (021b); The inner end surface of the first clamping ring (96) and the inner end surface of the second clamping ring (96-1) are respectively covered on the outer side of the inner ring end surface unloading step (101) of the two side ribs (021); The inner end surface of the first clamping ring (96) and the inner end surface of the second clamping ring (96-1) respectively enclose the step vertical surface (104) of the corresponding side inner ring end surface unloading step (101) and the step bottom surface (105) of the corresponding side inner ring end surface unloading step (101), forming an energy absorption cavity (102) on the two axial sides of the inner ring (02) respectively.

2. Double row roller bearing according to claim 1, characterized in that The overrun groove (022) is arc-shaped, and the lowest point of the circular arc of the overrun groove (022) is located at the radially innermost root of the rib (021); the step bottom surface (105) of the inner ring end surface unloading step (101) is located radially outwardly of the lowest point of the circular arc of the overrun groove (022); The rib inner side surface (021a) has an inclination angle from inside to outside, and the value of the inclination angle is 10'-30'.

3. Double row roller bearing according to claim 2, characterized in that: The two ribs (021) of the inner ring (02) define an interval for accommodating the rollers (03); the outer circumferential surface of the inner ring (02) in the interval forms an inner ring raceway surface (023) abutting the rollers (03); the radial height of the inner ring raceway surface (023) is the same as the radial height of the step bottom surface (105) of the inner ring end surface unloading step (101).

4. Double row roller bearing according to any of claims 1 to 3, characterized in that: The axial vertical distance between the step elevation (104) of the inner ring end face unloading step (101) and the plane where the contact reference surface (101a) is located is the axial depth of the energy absorption cavity (102); the overall thickness of the flange (021) along the axial direction of the double-row roller bearing is the total axial thickness of the flange; the axial depth of the energy absorption cavity (102) is 1 / 5 to 1 / 3 of the total axial thickness of the flange.

5. Double row roller bearing according to any of claims 1 to 3, characterized in that: Also includes: The retainer seat (04) is divided into an upper retainer half ring (04-1) and a lower retainer half ring (04-2) by a horizontal split plane. The retainer end cap (41) is located in the axial position of the retainer seat (04) and is used to hold the roller (03) between the retainer end cap (41) and the retainer seat (04); Multiple tungsten alloy counterweight columns (400) are divided into a first counterweight array and a second counterweight array. The first counterweight array is arranged in the upper half of the retainer semi-ring (04-1), and the second counterweight array is arranged in the lower half of the retainer semi-ring (04-2). The outer circumference of the tungsten alloy counterweight column (400) is provided with threads, and the tungsten alloy counterweight column (400) is connected to the retainer end cap (41) and the retainer seat (04) by threads.

6. Double row roller bearing according to claim 5, characterized in that: Both the first and second counterweight arrays contain two tungsten alloy counterweight columns (400). In the upper half of the retainer semi-ring (04-1), the two tungsten alloy counterweight columns (400) are symmetrically arranged on both sides of the midpoint of the circumference of the upper half of the retainer semi-ring (04-1); in the lower half of the retainer semi-ring (04-2), the two tungsten alloy counterweight columns (400) are symmetrically arranged on both sides of the midpoint of the circumference of the lower half of the retainer semi-ring (04-2).

7. Double row roller bearing according to claim 6, characterized in that Multiple windows (401) for accommodating rollers (03) are arranged at intervals along the circumferential direction on the outer circumferential surface of the upper half retainer half ring (04-1) and the outer circumferential surface of the lower half retainer half ring (04-2). A solid metal beam (402) is formed between adjacent windows (401). A cylindrical hole (403) is opened in the solid metal beam (402) along the axial direction of the retainer seat (04). A tungsten alloy counterweight column (400) is installed in the cylindrical hole (403).

8. Double row roller bearing according to claim 7, characterized in that: The retainer seat (04) has an even number of windows (401); the even number of windows (401) are divided into two groups of equal number, which are respectively arranged in the upper half retainer half ring (04-1) and the lower half retainer half ring (04-2); The window holes (401) in the upper half of the retainer semi-ring (04-1) are evenly and equidistantly distributed along the circumference, and the included angle between adjacent window holes (401) and between adjacent solid metal beams (402) is a fixed division angle; the window holes (401) in the lower half of the retainer semi-ring (04-2) are evenly and equidistantly distributed along the circumference, and the included angle between adjacent window holes (401) and between adjacent solid metal beams (402) is also the fixed division angle; The two tungsten alloy counterweight columns (400) inside the upper half retainer half ring (04-1) are respectively installed in the two solid metal beams (402) on both sides of the window hole (401) located at the midpoint of the circumference of the upper half retainer half ring (04-1). The angle formed by the center line of the two tungsten alloy counterweight columns (400) inside the upper half retainer half ring (04-1) and the center of the retainer seat (04) is equal to the fixed division angle. The two tungsten alloy counterweight columns (400) inside the lower half retainer half ring (04-2) are respectively installed in the two solid metal beams (402) on both sides of the window hole (401) located at the midpoint of the circumference of the lower half retainer half ring (04-2). The angle formed by the center line of the two tungsten alloy counterweight columns (400) inside the lower half retainer half ring (04-2) and the center of the retainer seat (04) is also equal to the fixed division angle.

9. Double row roller bearing according to claim 5, characterized in that: Both ends of the joint interface between the upper half retainer half ring (04-1) and the lower half retainer half ring (04-2) are provided with corresponding internal positioning pin holes (405); an internal positioning pin (406) is inserted into the internal positioning pin hole (405), and the internal positioning pin (406) spans the joint interface to limit the relative misalignment between the upper half retainer half ring (04-1) and the lower half retainer half ring (04-2).

10. Double row roller bearing according to any of claims 1 to 3, characterized in that It also includes an outer ring (01) and a second outer ring (21); the outer ring (01) and the second outer ring (21) are provided with a main positioning hole in their lateral engagement end faces; a main positioning pin (56) and an anti-detachment pin (56-1) are assembled between the lateral engagement end faces of the outer ring (01) and the second outer ring (21); the main positioning pin (56) is assembled inside the main positioning hole to establish the assembly positioning reference between the outer ring (01) and the second outer ring (21); the main positioning pin (56) is provided with an anti-detachment pin hole that penetrates its main body in the lateral direction, and the anti-detachment pin (56-1) is inserted into the anti-detachment pin hole to limit the radial slippage or detachment of the main positioning pin (56).

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