A device for induction hardening of a surface of a cup of a tapered roller bearing and an inductor thereof

Abstract

The present application relates to the technical field of induction quenching, in particular to a kind of surface induction quenching device of tapered roller bearing ring and its inductor.The inductor of the surface induction quenching device of tapered roller bearing ring includes coil and magnetic conductor arranged on the coil, the magnetic conductor has the large end heating section for heating the large end of ring and the small end heating section for heating the small end of ring, the size relationship of large end heating section and small end heating section satisfies that the magnetic field intensity of the large end area of ring is greater than the magnetic field intensity of the small end area of ring when inductor is used.The effective magnetic field of large end area is stronger than conventional magnetic conductor, targeted strengthening heating is realized, so as to balance the heating temperature field of quenching surface of uneven wall thickness ring, which is beneficial to the synchronous reaching of sufficient austenitizing temperature of large end and small end of ring in quenching process, effectively eliminates large end soft point, solves non-martensite organization problem, and prolongs bearing fatigue life.

Description

Technical Field

[0001] This invention relates to the field of induction hardening technology, specifically to an induction hardening device and its inductor for tapered roller bearing rings. Background Technology

[0002] Bearings directly determine the performance, level, quality, and reliability of equipment. They are the foundation upon which modern industry survives and develops. Bearings are one of the most important key components and are known as the "joints of high-end equipment." They are widely used in major equipment fields such as wind power generation, mining machinery, precision machine tools, metallurgical equipment, heavy equipment, high-end cars, high-speed trains, and aerospace.

[0003] The bearing inner ring is a crucial component of a bearing. During service, it is subjected to alternating loads, with fatigue spalling being the primary failure mode. Therefore, bearing inner rings are required to possess high resistance to plastic deformation, friction and wear, high rotational and dimensional accuracy, high dimensional stability, long service life, and high reliability. To achieve these requirements, surface strengthening heat treatment is necessary. Currently, surface strengthening methods for bearing inner rings include surface carburizing and induction hardening. Surface carburizing has a long production cycle, wastes a lot of energy, and results in a shallow carburized layer. Induction hardened parts exhibit high hardness, high strength, high toughness, stable quality, high production efficiency, and are easily automated.

[0004] For decades, the primary design goals for large-size bearings have been absolute reliability and ultimate load-bearing capacity. Limited by materials science, analytical tools, and manufacturing processes, designers generally adopted conservative and redundant designs, resulting in exceptionally heavy and expensive bearings. In recent years, with the limits of application scale, the extreme pressures of economic efficiency and environmental protection, and the extreme demands of performance requirements, bearings face a "weight crisis" and immense cost pressure. Under this contradiction, combining existing digital design tools and advanced materials, the design philosophy for large-size bearings has pursued extreme lightweighting and cost optimization, resulting in large-size bearing components with poor rigidity and thin walls. Simultaneously, due to their harsh operating conditions, the hardened layer depth and hardness of the raceway surface after quenching must be uniform and controllable in both the circumferential and axial directions, placing unprecedented and almost contradictory high demands on the heat treatment process.

[0005] Currently, induction hardening technology without soft strips is receiving significant attention as a new technological approach due to its outstanding comprehensive advantages, and this heat treatment process is expected to have a wide range of applications in the future. For bearing parts with simple structures, uniform cross-sectional dimensions, good rigidity, and large wall thickness, continuous scanning medium-frequency induction hardening technology can achieve uniform hardness and hardened layer depth throughout the raceway after quenching. However, for asymmetrical single-row tapered roller bearings with abrupt cross-sectional changes, the current induction hardening heat treatment process still has significant shortcomings.

[0006] Regarding some existing induction hardening techniques for tapered roller bearing rings: Chinese invention patent application CN119040610A discloses a positioning method for medium-frequency heating and quenching of the inner ring of a wind turbine main shaft bearing. This method involves placing the inner ring of the bearing on a support ring that can rotate around its own axis, and setting a mandrel on the circumference of the support ring to apply an elastic force to the inner ring. During induction heating and subsequent quenching and cooling, even if the inner ring expands due to heat, the axis of the inner ring can be prevented from shifting, which is beneficial to improving the quality of heat treatment. Furthermore, the force applied to the inner ring by the mandrel during the quenching and cooling stage can achieve shape-limiting quenching of the ring, avoiding excessive deformation.

[0007] Furthermore, Chinese invention patent CN118621129B discloses a form-limiting and round-preserving fixture and method for induction hardening of bearing rings in a single-row tapered roller bearing for wind turbines. This method employs a non-soft-strip scanning induction hardening technique. Clockwise and counterclockwise scanning inductors scan the raceway from two directions starting from the initial point, simultaneously reaching the end point to complete the hardening process. The form-limiting and round-preserving fixture provides radial pre-tightening to the entire workpiece, preventing localized shrinkage caused by localized expansion and absorbing heat from the back of the workpiece to reduce thermal expansion and prevent large deformation. The main research direction of these tapered roller bearing ring induction hardening technologies is to utilize fixtures to limit the bearing rings, i.e., to use form-preserving fixtures to reduce ring deformation during heat treatment.

[0008] To improve heating efficiency and uniformity, a magnetic conductor is fixed to the coil of the inductor. High magnetic permeability (ferrite / silicon steel sheet) is used to gather divergent magnetic lines of force to the workpiece heating zone, significantly increasing eddy current density and heating efficiency in this area, enhancing current flow efficiency, and reducing magnetic leakage. The structure of this inductor can be found in the optimized inductor structure for induction hardening of the surface of a thrust ball bearing raceway, disclosed in Chinese Utility Model Patent No. CN208898942U. The inductor includes a first magnetic conductor, a secondary heating copper tube, a main heating copper tube, a second magnetic conductor, a cooling water box, and a connecting frame. The main heating copper tube is a bent rectangular cross-section copper tube, and the secondary heating copper tube is fixed to the main heating copper tube by the connecting frame. The secondary heating copper tube is also bent a rectangular cross-section copper tube. The connecting frame is bent a square cross-section copper tube. The second magnetic conductor and the first magnetic conductor are respectively installed on the main heating copper tube and the secondary heating copper tube. A cooling water box is located next to the main heating copper tube, and the cooling water box has several spray holes.

[0009] The magnetic conductor has a U-shaped cross-section, while the copper tube is rectangular. The side of the rectangular tube facing the workpiece does not have a magnetic conductor. The U-shaped magnetic conductor is fitted and fixed to the other three sides of the rectangular tube. In other words, the rectangular tube is covered with magnetic conductors on all three sides except the side facing the workpiece. The side of the rectangular tube facing the workpiece and the side of the magnetic conductor facing the workpiece constitute the sensing surface of the inductor, which corresponds to the hardened surface of the workpiece. To ensure consistent spacing between the sensing surface and the hardened surface, the sensing surface of the inductor typically adopts a structure that mimics the shape of the hardened surface of the workpiece.

[0010] Because the raceway of a tapered roller bearing is a conical surface with a drastic change in cross-section, and the inner ring also has end flanges and oil grooves that need to be quenched, and with the current lightweight design of bearing structures, the overall wall thickness of the inner ring is relatively small. During induction heating, the thin-walled small end, sharp corners and edges will produce a "sharp corner effect", and the temperature is very easy to overheat. When the quenching liquid is sprayed for cooling, quenching cracks are very likely to be generated on the surface of the small end, affecting the heat treatment quality and reducing the yield. In order to avoid overheating of the small end of the ring, the overall temperature needs to be reduced. However, this may result in insufficient heating in the thick-walled area of ​​the large end of the ring (such as the root of the flange) to produce non-marginal structures, causing the workpiece to be scrapped.

[0011] Combination Figure 1 The inner ring has a partial structure with a tapered raceway 11 on its outer circumference and large flanges 12 and small flanges 13 at both ends. The end with the large flange is the large end of the inner ring, and the end with the small flange is the small end of the inner ring. The wall thickness of the large end and the wall thickness of the small end are significantly different. Under the same conditions, when the small end reaches the set temperature, the temperature of the large end is relatively low. This may result in non-marginal structures due to insufficient heating, causing the workpiece to be scrapped. Summary of the Invention

[0012] The purpose of this invention is to provide an inductor for a surface induction hardening device for tapered roller bearing rings, so as to solve the problem that insufficient heating is likely to occur at the large end of tapered roller bearing rings after surface induction hardening. Another purpose of this invention is to provide a surface induction hardening device for tapered roller bearing rings using this inductor, so as to solve the above-mentioned problems.

[0013] The technical solution of the inductor in the induction hardening device for tapered roller bearing rings of the present invention is as follows: An inductor for a surface induction hardening device for tapered roller bearing rings includes a coil and a magnetic conductor disposed on the coil. The magnetic conductor has a large-end heating section for heating the large end of the ring and a small-end heating section for heating the small end of the ring. The cross-sectional area of ​​the large-end heating section is larger than that of the small-end heating section. The dimensional relationship between the large-end heating section and the small-end heating section satisfies the requirement that the magnetic field strength in the large-end region of the ring is greater than that in the small-end region of the ring when the inductor is in use.

[0014] Beneficial Effects: This invention addresses the problem of insufficient heating at the large end of tapered roller bearing rings after induction hardening. It provides a variable magnetic field inductor, where the heating sections at the large and small ends of the inductor are of different sizes. Through physical structure, the distribution of the induced magnetic field is actively reshaped. During operation, the magnetic field strength at the large end of the ring is greater than that at the small end, directing more electromagnetic energy to the thick-walled region at the large end. This results in a stronger effective magnetic field at the large end than with conventional magnetic conductors, enabling targeted and enhanced heating. This balances the heating temperature field on the quenched surface of rings with uneven wall thickness, facilitating simultaneous austenitization at both the large and small ends during quenching. It effectively eliminates soft spots at the large end, solves non-marginal structure problems, and ultimately extends the bearing's fatigue life.

[0015] Furthermore, the portion of the magnetic conductor located on the corresponding side of the coil has a width direction perpendicular to the side of the coil on which it is located; on the same side of the coil, the width of the large-end heating section is greater than the width of the small-end heating section.

[0016] Beneficial effects: By making the widths of the large-end heating section and the small-end heating section of the magnetic conductor different, the cross-sectional area of ​​the large-end heating section is larger than that of the small-end heating section, thereby enhancing the effect of the large-end heating section on magnetic field control and optimization.

[0017] Furthermore, the large end heating section has a raceway corresponding portion for corresponding to the raceway of the ring and a large flange corresponding portion for corresponding to the inner side of the large flange of the ring, and the width of the raceway corresponding portion is smaller than the width of the large flange corresponding portion.

[0018] Beneficial effects: The width of the large-end heating section itself also changes, which can adapt to the wall thickness variation of the large end of the ring in the extension direction of the large-end heating section. The large-end heating section has a corresponding raceway, which is conducive to the full heating of the entire area of ​​the large end of the ring.

[0019] Furthermore, the cross-sectional area of ​​the large-end heating segment decreases from the direction away from the small-end heating segment to the direction closer to the small-end heating segment, and the width of the end of the large-end heating segment that is connected to the small-end heating segment is smaller than the width of the end that is away from the small-end heating segment.

[0020] Beneficial effect: It also changes the width of the large-end heating section, which can adapt to the wall thickness variation of the large end of the ring in the extension direction of the large-end heating section.

[0021] Furthermore, the large-end heating section has at least two sections with different widths, wherein the section with the smallest width is connected to the small-end heating section and its width is greater than that of the small-end heating section, and the side of the large-end heating section in the width direction is a stepped surface.

[0022] Beneficial effects: It allows the width of the magnetic conductor to decrease in a stepped manner, and different segments can be formed by combining silicon steel sheet units of different widths along the axial direction, which facilitates manufacturing.

[0023] Furthermore, the width of the large-end heating section gradually decreases from the direction away from the small-end heating section to the direction closer to the small-end heating section, and the side of the large-end heating section in the width direction is an inclined surface.

[0024] Beneficial effect: It allows the width of the magnetic conductor to decrease gradually, which can adapt to the parts where the wall thickness of the ring gradually changes.

[0025] Furthermore, the width of the large-end heating section gradually decreases from the direction away from the small-end heating section to the direction closer to the small-end heating section, and the side of the large-end heating section in the width direction is an arc surface.

[0026] Beneficial effect: It allows the width of the magnetic conductor to decrease gradually, which can adapt to the parts where the wall thickness of the ring gradually changes.

[0027] Furthermore, the connection position between the large-end heating section and the small-end heating section satisfies the requirement that it radially corresponds to the equivalent wall thickness position of the collar when the sensor is in use.

[0028] Beneficial effect: It allows the heating section at the large end to have sufficient extension length, which is beneficial for fully heating the large end area of ​​the ring.

[0029] The technical solution of the tapered roller bearing ring surface induction hardening device of the present invention is as follows: A surface induction hardening device for tapered roller bearing rings includes a hardening apparatus and a fixture for clamping and fixing the rings. The hardening apparatus includes an inductor, which includes a coil and a magnetic conductor disposed on the coil. The magnetic conductor has a large-end heating section for heating the large end of the ring and a small-end heating section for heating the small end of the ring. The cross-sectional area of ​​the large-end heating section is larger than that of the small-end heating section. The dimensional relationship between the large-end heating section and the small-end heating section satisfies the requirement that the magnetic field strength in the large-end region of the ring is greater than that in the small-end region when the inductor is in use.

[0030] Beneficial Effects: This invention addresses the problem of insufficient heating at the large end of tapered roller bearing rings after induction hardening. It provides a variable magnetic field inductor, where the heating sections at the large and small ends of the inductor are of different sizes. Through physical structure, the distribution of the induced magnetic field is actively reshaped. During operation, the magnetic field strength at the large end of the ring is greater than that at the small end, directing more electromagnetic energy to the thick-walled region at the large end. This results in a stronger effective magnetic field at the large end than with conventional magnetic conductors, enabling targeted and enhanced heating. This balances the heating temperature field on the quenched surface of rings with uneven wall thickness, facilitating simultaneous austenitization at both the large and small ends during quenching. It effectively eliminates soft spots at the large end, solves non-marginal structure problems, and ultimately extends the bearing's fatigue life.

[0031] Furthermore, the portion of the magnetic conductor located on the corresponding side of the coil has a width direction perpendicular to the side of the coil on which it is located; on the same side of the coil, the width of the large-end heating section is greater than the width of the small-end heating section.

[0032] Beneficial effects: By making the widths of the large-end heating section and the small-end heating section of the magnetic conductor different, the cross-sectional area of ​​the large-end heating section is larger than that of the small-end heating section, thereby enhancing the effect of the large-end heating section on magnetic field control and optimization.

[0033] Furthermore, the large end heating section has a raceway corresponding portion for corresponding to the raceway of the ring and a large flange corresponding portion for corresponding to the inner side of the large flange of the ring, and the width of the raceway corresponding portion is smaller than the width of the large flange corresponding portion.

[0034] Beneficial effects: The width of the large-end heating section itself also changes, which can adapt to the wall thickness variation of the large end of the ring in the extension direction of the large-end heating section. The large-end heating section has a corresponding raceway, which is conducive to the full heating of the entire area of ​​the large end of the ring.

[0035] Furthermore, the cross-sectional area of ​​the large-end heating segment decreases from the direction away from the small-end heating segment to the direction closer to the small-end heating segment, and the width of the end of the large-end heating segment that is connected to the small-end heating segment is smaller than the width of the end that is away from the small-end heating segment.

[0036] Beneficial effect: It also changes the width of the large-end heating section, which can adapt to the wall thickness variation of the large end of the ring in the extension direction of the large-end heating section.

[0037] Furthermore, the large-end heating section has at least two sections with different widths, wherein the section with the smallest width is connected to the small-end heating section and its width is greater than that of the small-end heating section, and the side of the large-end heating section in the width direction is a stepped surface.

[0038] Beneficial effects: It allows the width of the magnetic conductor to decrease in a stepped manner, and different segments can be formed by combining silicon steel sheet units of different widths along the axial direction, which facilitates manufacturing.

[0039] Furthermore, the width of the large-end heating section gradually decreases from the direction away from the small-end heating section to the direction closer to the small-end heating section, and the side of the large-end heating section in the width direction is an inclined surface.

[0040] Beneficial effect: It allows the width of the magnetic conductor to decrease gradually, which can adapt to the parts where the wall thickness of the ring gradually changes.

[0041] Furthermore, the width of the large-end heating section gradually decreases from the direction away from the small-end heating section to the direction closer to the small-end heating section, and the side of the large-end heating section in the width direction is an arc surface.

[0042] Beneficial effect: It allows the width of the magnetic conductor to decrease gradually, which can adapt to the parts where the wall thickness of the ring gradually changes.

[0043] Furthermore, the connection position between the large-end heating section and the small-end heating section satisfies the requirement that it radially corresponds to the equivalent wall thickness position of the collar when the sensor is in use.

[0044] Beneficial effect: It allows the heating section at the large end to have sufficient extension length, which is beneficial for fully heating the large end area of ​​the ring.

[0045] Furthermore, the tooling is provided with an annular heat-absorbing step surface for fitting with the small end of the ferrule. The annular heat-absorbing step surface has a back heat-absorbing ring surface that surrounds its center line and extends along the center line direction, and an end heat-absorbing ring surface that is perpendicular to its center line. The back heat-absorbing ring surface is used to radially correspond to the circumferential surface of the ferrule on the side opposite to the raceway, and the end heat-absorbing ring surface is used to contact the end face of the small end of the ferrule. The dimension of the back heat-absorbing ring surface along the center line direction is not less than the axial width of the small flange of the small end of the ferrule. The dimension of the end heat-absorbing ring surface perpendicular to the center line direction is such that after the ferrule is installed, the small flange of the small end of the ferrule does not protrude radially beyond the end heat-absorbing ring surface, so that the tooling absorbs the heat at the small flange of the ferrule during quenching.

[0046] Beneficial Effects: This invention addresses the problem of quenching cracks easily appearing at the small end of tapered roller bearing rings after surface induction hardening. It provides a surface induction hardening fixture for tapered roller bearing rings that can suppress quenching cracks. The tapered roller bearing ring is mounted on the annular heat-absorbing step surface of the fixture. The back heat-absorbing ring surface of the annular heat-absorbing step surface radially corresponds to the circumferential surface of the ring on the side facing away from the raceway. The end heat-absorbing ring surface contacts the end face of the small end of the ring, and the axial extension dimension of the back heat-absorbing ring surface is not less than the axial width of the small flange. The radial dimension of the end heat-absorbing ring surface satisfies the requirements of the small flange. The edge does not protrude radially beyond the end heat-absorbing ring surface, so that the back heat-absorbing ring surface covers the back of the small side edge, and the end heat-absorbing ring surface covers the end face of the small side edge. The annular heat-absorbing step covers the non-quenched surface of the small end of the ring. Thus, when the surface of the small side edge at the small end is quenched, the tooling can absorb the heat at the small end. The excess heat accumulated in the thin-walled small end area of ​​the workpiece can be conducted away in real time by the heat-absorbing tooling through the contact interface of the tooling, thereby suppressing overheating in this area and preventing cracking during subsequent continuous cooling. It is less prone to quenching cracks and avoids scrapping of the workpiece. It is especially suitable for large-size thin-walled bearing rings.

[0047] Furthermore, the tooling includes a heat-absorbing ring, with an annular heat-absorbing step surface disposed on one side circumferential surface of the heat-absorbing ring for mating with the collar; the wall thickness at one end of the section containing the back heat-absorbing ring surface of the heat-absorbing ring is greater than the wall thickness at the other end, and the end with the larger wall thickness of the section containing the back heat-absorbing ring surface of the heat-absorbing ring is connected to the end heat-absorbing ring surface.

[0048] Beneficial effects: Using the heat-absorbing ring as the mounting base for the bearing ring facilitates heat dissipation through the internal space of the heat-absorbing ring, allowing the thicker end to be closer to the smaller end of the ring and the thinner end to be closer to the larger end of the ring. This reduces the influence of the tooling on the temperature of the larger end and helps improve the consistency of temperature changes between the larger and smaller ends of the ring.

[0049] Furthermore, the end with the larger wall thickness of the section containing the back heat-absorbing ring surface of the heat-absorbing ring satisfies that the wall thickness is not less than the equivalent wall thickness of the collar; the dimension of the back heat-absorbing ring surface along the centerline direction satisfies that it is not less than the distance between the cross section containing the equivalent wall thickness of the collar and the small end face.

[0050] Beneficial effect: The heat-absorbing ring on the back fully covers the back of the small end of the collar, which helps to improve the heat absorption effect.

[0051] Furthermore, the tooling has an end face opposite to the end heat-absorbing ring surface, and a ring platform is formed in the portion of the tooling between the end face and the end heat-absorbing ring surface. The dimension of the ring platform along the center line direction is not less than the axial width of the small flange of the collar.

[0052] Beneficial effect: It makes the part of the tooling located on one side of the small end face of the ring have sufficient width, which is conducive to improving the heat absorption effect.

[0053] Furthermore, the tooling has an end peripheral surface located on the side away from the back heat-absorbing ring surface of the end heat-absorbing ring surface, the end heat-absorbing ring surface is in contact with the end peripheral surface, and the end peripheral surface is flush with the outer peripheral surface of the small stop after the ring is installed.

[0054] Beneficial effects: By aligning the peripheral surface of the tooling near the small end of the ferrule with the outer peripheral surface of the small flange of the ferrule, and ensuring the tooling does not protrude radially beyond the outer peripheral surface of the small end of the ferrule, interference with the inductor of the quenching equipment can be avoided. This allows the inductor to be positioned closer to the quenching surface of the ferrule, improving heating efficiency. Simultaneously, the outer peripheral surface of the small end of the ferrule does not protrude from the tooling; otherwise, during the quenching process, cracks would form along the outer edge of the small end of the ferrule due to high temperature and rapid cooling.

[0055] Furthermore, the back heat-absorbing annular surface is designed to maintain a gap of 0.3-0.8 mm with the circumferential surface of the raceway opposite to the raceway after the raceway is installed.

[0056] Beneficial effects: While ensuring good heat absorption, it facilitates the assembly of rings and tooling, and makes it easier to manufacture and process large-size tooling.

[0057] Furthermore, the tooling has a large end mating ring surface located on the side of the back heat-absorbing ring surface away from the end heat-absorbing ring surface. After the ring is installed on the tooling, the large end mating ring surface is closer to the large end of the ring than the back heat-absorbing ring surface, and the gap between the large end mating ring surface and the ring's circumferential surface facing away from the raceway is greater than the gap between the back heat-absorbing ring surface and the ring's circumferential surface facing away from the raceway.

[0058] Beneficial effect: While satisfying the heat absorption capacity of the tooling for the small end, it reduces the heat absorption capacity of the tooling for the large end of the ring, which is conducive to improving the synchronization of heating temperature between the large and small ends of the ring.

[0059] Furthermore, an annular heat-absorbing step surface is provided on the outer circumferential surface of the tooling for quenching the inner ring of the single-row tapered roller bearing. The outer circumferential surface of the inner ring is provided with a large flange and a small flange at both ends. The large flange is located at the large end of the inner ring, and the small flange is located at the small end of the inner ring. The inner circumferential surface of the inner ring is a cylindrical surface. The outer diameter of the large end of the inner ring is larger than the outer diameter of the small end, and the wall thickness of the large end is larger than the wall thickness of the small end. The quenching surface of the inner ring includes the raceway surface, the large flange surface, and the small flange surface. The height of the large flange protruding relative to the raceway is greater than the height of the small flange protruding relative to the raceway. The top surface of the large flange and the small flange in the protruding direction is its outer circumferential surface.

[0060] Beneficial effect: This tooling absorbs heat from the small end of the inner ring, preventing overheating of the sharp corners and edges of the small end.

[0061] Furthermore, the tooling includes a pressing block for pressing the large end of the ferrule to press the small end of the ferrule against the heat-absorbing ring surface at the end. Multiple pressing blocks are distributed in the direction surrounding the center line, and within the same angular range, the number of pressing blocks in the quenching end region is greater than the number of pressing blocks in the quenching start region.

[0062] Beneficial effects: During continuous scanning induction hardening, the deformation of the ring will be more concentrated in the end area of ​​the hardening process. By setting more pressure blocks in this area, a more sufficient and uniform clamping force can be provided to suppress the deformation of the ring. At the same time, the pressure blocks can ensure that the small end of the ring is in close contact with the heat-absorbing surface of the tooling, improve the heat conduction effect, and prevent quenching cracks. Attached Figure Description

[0063] Figure 1 This is a partial structural diagram of the inner ring of a tapered roller bearing; Figure 2 This is a schematic diagram illustrating the mating relationship between the inner ring of the tapered roller bearing and a matching inductor in an embodiment of the tapered roller bearing surface induction hardening device of the present invention. Figure 3 for Figure 2 A schematic diagram of the sensor's sensing surface from one side of the sensor; Figure 4 for Figure 2 A schematic diagram of the sensor's structure from the side facing away from the sensing surface; Figure 5 for Figure 2 A front view of the sensor's sensing surface from one side; Figure 6This is a schematic diagram of another structure of the inductor in an embodiment of the tapered roller bearing ring surface induction hardening device of the present invention; Figure 7 This is a schematic diagram of another structure of the inductor in an embodiment of the tapered roller bearing ring surface induction hardening device of the present invention; Figure 8 This is a schematic diagram of the tooling and bearing mating structure of an embodiment of the tapered roller bearing ring surface induction hardening device of the present invention; Figure 9 for Figure 8 A top view of the tooling and ferrule installation structure. Figure 10 for Figure 8 A schematic diagram of the mating parts between the bearing rings and the tooling; Figure 11 This is a schematic diagram of another tooling and bearing mating structure in an embodiment of the tapered roller bearing ring surface induction hardening device of the present invention; Figure 12 This is a schematic diagram of the fitting structure between a tooling and a bearing ring in another embodiment of the tapered roller bearing surface induction hardening device of the present invention. Figure 13 for Figure 12 A schematic diagram of the mating parts between the bearing rings and the tooling.

[0064] In the diagram: 1. Inner ring; 11. Raceway; 12. Large flange; 13. Small flange; 2. Heat absorption ring; 21. Back heat absorption ring surface; 22. End heat absorption ring surface; 23. End circumferential surface; 24. Large end mating ring surface; 3. Press block; 101. Coil; 1011. Raceway heating section; 1012. Large side heating section; 1013. Small side heating section; 102. Magnetic conductor; 1021. Large end heating section; 1022. Small end heating section. Detailed Implementation

[0065] The basic concept of the inductor in the tapered roller bearing ring surface induction hardening device of the present invention is to actively reshape the distribution of the induced magnetic field through physical structure, and to directionally couple more electromagnetic energy to the thick-walled region of the large end of the bearing ring. This allows the large end region to obtain a stronger effective magnetic field than conventional magnetic conductors, achieving targeted enhanced heating. This balances the heating temperature field of the quenching surface of the ring with uneven wall thickness, which is beneficial for the large and small ends of the ring to reach sufficient austenitization temperature simultaneously during the quenching process. This ensures that the small end does not overheat and that the large end is fully heated, effectively eliminating soft spots at the large end, solving the non-Marsh structure problem, and extending the bearing fatigue life.

[0066] The following is a detailed description with reference to specific embodiments.

[0067] An embodiment of the tapered roller bearing ring surface induction hardening device of the present invention: In this embodiment, the induction hardening device for the inner rings of a tapered roller bearing is used to perform induction hardening on the inner rings of the tapered roller bearing. The device includes a hardening apparatus and a fixture for clamping and fixing the rings. The hardening apparatus includes an inductor. The tapered roller bearing is a single-row tapered roller bearing, and the inner ring is the ring to be hardened; the inner ring is also the inner ring of the bearing, i.e., the workpiece to be processed.

[0068] To facilitate understanding, let's first combine... Figure 1 The inner ring structure is described as follows: the outer circumference of the inner ring is provided with a conical raceway 11 and two large flanges 12 and small flanges 13 at both ends. The large flange 12 is located at the large end of the inner ring, and the small flange 13 is located at the small end of the inner ring. The inner circumference of the inner ring is a cylindrical surface. The outer diameter of the large end of the inner ring is larger than the outer diameter of the small end, and the wall thickness of the large end is larger than the wall thickness of the small end. The large end of the raceway 11 is connected to the large flange 12, and the small end is connected to the small flange 13. The height of the large flange 12 protruding relative to the raceway 11 is greater than the height of the small flange 13 protruding relative to the raceway 11. The protrusion direction is radial to the ring. The top surface of the protrusion direction of the large flange 12 and the small flange 13 is its outer circumference surface, and this outer circumference surface is a cylindrical surface. The diameter of the circle containing the outer circumference surface of the large flange 12 is greater than the diameter of the circle containing the outer circumference surface of the small flange 13. The raceway 11 is an outer conical surface. Both the large flange 12 and the small flange 13 have two axial sides. The side away from the raceway 11 is part of the corresponding end face of the raceway, while the side connected to the raceway 11 is used to limit the end face of the tapered roller.

[0069] The quenching surface of the inner ring includes the surface of the raceway 11, the surface of the large flange 12, and the surface of the small flange 13. The surfaces of the raceway 11, the large flange 12, and the small flange 13 are all directly opposite the corresponding parts of the sensing surface of the sensor. The axial inner side of the large flange 12 surface near the raceway 11 and the axial inner side of the small flange 13 surface near the raceway 11 constitute the surface corresponding to the sensing surface of the sensor and form part of the quenching surface.

[0070] Due to the uneven wall thickness of tapered roller bearing rings, the difference between the wall thickness at the large end and the small end is significant, especially in bearings with large diameters and widths where the difference is even more pronounced. This thick-walled area (such as the root of the large flange) may then suffer from insufficient heating, resulting in non-martensitic structures and rendering the workpiece unusable. To address the problem of insufficient heating and the formation of non-martensitic structures during induction hardening caused by the thick wall at the large end of the inner ring, this invention provides an inductor structure with adaptive magnetic field control.

[0071] like Figure 2 , Figure 3 , Figure 4 , Figure 5As shown, the inductor includes a coil 101 and a magnetic conductor 102. The inductor is a contoured structure identical to the quenched surface structure of the workpiece, and its quenching gap is consistent with that of the inner ring 1 raceway and the large and small flanges. The magnetic conductor 102 is disposed on the corresponding quenched surface portion of the coil 101. The core of the inductor is to ensure that the magnetic field strength in the large end region of the ring is greater than that in the small end region of the ring.

[0072] Figure 2 The image only shows a portion of coil 101. The complete coil 101 of the sensor includes two main segments spaced apart from each other and an intermediate segment connecting the two main segments. Figure 2 The diagram only shows one of the main sections. The two main sections are parallel and opposite to the inner ring 1. The middle section is perpendicular to the main section. Both the middle section and the main section can be made of copper pipes. The middle section and the main section can be connected or not connected. When not connected, circulating cooling water is supplied inside a single main section. When connected, the two main sections and the middle section belong to one cooling water passage. Figure 2 The diagram shows one of the main sections of the coil 101 and the magnetic conductor 102 thereon. The copper tube forming the coil 101 is a rectangular tube with a side facing the quenching surface, which is also the induction surface of the coil 101. In use, the induction surface is opposite to the quenching surface. The induction surface is generally a contour surface. The rectangular tube of the main section is bent according to the zigzag direction of the flange and the raceway surface.

[0073] The magnetic conductor 102 is disposed on the main section and on the other three sides of the copper tube other than the sensing surface. The magnetic conductor 102 can adopt a U-shaped structure and fit and engage on the three sides of the rectangular tube. The open end of the U-shape faces the inner ring 1. The U-shaped structure includes two opposing sides and a middle part connecting the two sides. The middle part is located on the side of the copper tube facing away from the inner ring 1. The two sides are respectively located on the opposite sides of the copper tube. The ends of the two sides away from the middle part form an opening and this end face is the side of the magnetic conductor 102 facing the inner ring 1, that is, the sensing surface of the magnetic conductor 102.

[0074] The width of the end of the magnetic conductor 102 corresponding to the large end of the collar is greater than the width of the end corresponding to the small end of the collar. The wider end is the large end of the magnetic conductor 102, and the narrower end is the small end of the magnetic conductor 102. The width variation section is mainly in the part above the middle of the magnetic conductor 102. The width direction is perpendicular to the side of the corresponding main segment, that is, perpendicular to the extension direction of the main segment.

[0075] The magnetic conductor 102 can be divided into upper and lower parts. The upper part is the large-end heating section 1021, and the lower part is the small-end heating section 1022. The large-end heating section 1021 is the width-varying section, with the wider end located in the large-end heating section 1021 and the narrower end located in the small-end heating section 1022. The large-end heating section 1021 heats the large end of the ring, and the small-end heating section 1022 heats the small end of the ring.

[0076] The cross-sectional area of ​​the large-end heating section 1021 is larger than that of the small-end heating section 1022, and the cross-section is perpendicular to the extension direction of the corresponding heating section. The portion of the magnetic conductor 102 located on the corresponding side of the coil 101 has a width direction perpendicular to the side of the coil on which it is located, and the width direction of the magnetic conductor 102 is also the spacing direction of the two opposite sides of the coil 101 on which it is located. On the same side of the coil 101, the width of the large-end heating section 1021 is larger than the width of the small-end heating section 1022. The portion of the magnetic conductor 102 in the corresponding large-end region of the inner ring 1 of the inductor is made wider, that is, the side width of the magnetic conductor 102 decreases.

[0077] The cross-sectional area of ​​the large-end heating section 1021 decreases from the direction away from the small-end heating section 1022 to the direction closer to the small-end heating section 1022. The width of the end of the large-end heating section 1021 that is connected to the small-end heating section 1022 is smaller than the width of the end that is away from the small-end heating section 1022, which adapts to the wall thickness variation of the large end of the ring.

[0078] Since the tortuous extension direction of the main section copper tube of coil 101 is adapted to the tortuous direction of the quenching surface of the coil, the main section of coil 101 has a raceway heating part 1011 that heats the surface of the raceway 11 corresponding to the raceway, a large side heating part 1012 that heats the inner side of the large side 12 corresponding to the raceway, and a small side heating part 1013 that heats the inner side of the small side 13 corresponding to the raceway. The extension direction of the raceway heating part 1011 is consistent with the generatrix direction of the conical surface of the raceway 11. The extension direction of the raceway heating part 1011 is perpendicular to that of the large side heating part 1012. The small side heating part 1013 forms an angle with the extension direction of the raceway heating part 1011. The sides of the large side heating part 1012, the small side heating part 1013, and the raceway heating part 1011 facing the quenching surface of the raceway constitute the induction surface of coil 101.

[0079] The large-end heating section 1021 of the magnetic conductor 102 has a portion fixed to the large flange heating section 1012 and a portion fixed to the raceway heating section 1011. The small-end heating section 1022 of the magnetic conductor 102 has a portion fixed to the small flange heating section 1013 and a portion fixed to the raceway heating section 1011. The portion of the small-end heating section 1022 fixed to the raceway heating section 1011 is connected to the portion of the large-end heating section 1021 fixed to the raceway heating section 1011. The width direction of the portions of the magnetic conductor 102 located on each side of the main section is perpendicular to the side of the main section where the corresponding portion is located.

[0080] The portion of the large-end heating section 1021 fixed to the large-side heating part 1012 is the portion corresponding to the large-side heating part that corresponds to the inner side of the large-side 12. The portion of the large-end heating section 1021 fixed to the raceway heating part 1011 is the portion corresponding to the raceway 11. The width of the portion of the large-end heating section 1021 fixed to the large-side heating part 1012 is greater than the width of the portion fixed to the raceway heating part 1011. The width decreases as it approaches the small-end heating section 1022. All portions of the small-end heating section 1022 have the same width.

[0081] The large-end heating section 1021 extends to the equivalent wall thickness of the collar, ensuring effective heating of the large end of the collar. The sensing surface of the magnetic conductor 102 is wider closer to the large end of the collar. The connection position between the large-end heating section 1021 and the small-end heating section 1022 corresponds radially to the equivalent wall thickness of the collar when the sensor is in use. The extension length of the large-end heating section 1021 can also be set as needed.

[0082] Combination Figure 5 The width of the magnetic conductor 102 can also gradually decrease from the larger end to the middle, that is, the upper side of the magnetic conductor 102 can be beveled, and the outer contour line of the upper side of the magnetic conductor 102 is a beveled line in the projection direction perpendicular to the induction surface. The side of the heating section 1021 at the larger end is beveled in the width direction. Accordingly, the magnetic conductor 102 can adopt an integral casting structure.

[0083] Combination Figure 6 The change from the wider end to the narrower end of the magnetic conductor 102 can be achieved using two or more magnetic sheets, which are silicon steel sheets. Figure 6 The magnetic conductor 102 employs three widths of magnetic sheets, and is divided into three segments from top to bottom, with the width decreasing from largest to smallest. Each segment contains multiple magnetic sheets, and the length of a segment is the sum of the thicknesses of the individual magnetic sheets within that segment. The magnetic sheets within the same segment have the same specifications. The different widths of the segments create a stepped structure on the outer surface of the magnetic conductor 102, forming a multi-layered composite structure. The side of the heating segment at the larger end has a stepped surface in the width direction. This magnetic conductor 102 is composed of silicon steel sheet units of at least two different widths combined axially, with its width decreasing in a stepped manner from the larger end to the middle. The magnetic conductors 102 on the two main segments of the coil 101 have a structure where the width decreases at the top and remains the same at the bottom.

[0084] Combination Figure 7 Alternatively, the upper side of the magnetic conductor 102 can be made into an arc surface, with the width gradually decreasing along the arc. The side of the heating section at the large end is also an arc surface in the width direction. The magnetic conductors 102 on both main sections of the coil 101 have a structure where the upper width decreases while the lower width remains the same.

[0085] In this embodiment, the magnetic conductor 102 has a structure with decreasing width at the top and a uniform width at the bottom. All parts of the magnetic conductor have the same dimensions in the direction perpendicular to the induction surface. All parts of the coil 101 have the same dimensions. The upper part of the magnetic conductor 102 on the side facing away from the induction surface of the coil has a uniform width. The widths of the two sides of the magnetic conductor 102 vary, while the width of the middle part on the back can be variable or constant. In other embodiments, the width of the lower side of the magnetic conductor can also vary, meaning the heating section at the small end also has a decreasing width from top to bottom. The overall cross-sectional area of ​​the magnetic conductor changes from top to bottom to match the change trend from the large end to the small end of the coil, ensuring that the effective magnetic field at the large end of the coil is stronger than the effective magnetic field at the small end, thus making the induction heating temperature of all parts of the coil more uniform.

[0086] By actively reshaping the distribution of the induced magnetic field through physical structure, while maintaining a relatively constant gap between the induction surface and the quenching surface, the size of the magnetic conductor corresponding to the rear wall region of the large end of the bearing ring is increased. This allows for the directional coupling of more electromagnetic energy to the raceway region of the thick-walled area at the large end of the bearing, resulting in a stronger effective magnetic field at the large end than that of a conventional single-width magnetic conductor. This targeted heating enhances the heating temperature field on the axial raceway surface of the workpiece, ensuring that the large and small ends reach the full austenitizing temperature simultaneously during the quenching process. This induction hardening method effectively eliminates soft spots at the large end, solves the non-Martian structure problem, and ultimately extends the fatigue life of the bearing.

[0087] By utilizing the physical structure of the composite magnetic conductor, the induced magnetic field is artificially reshaped, efficiently and directionally replenishing the potentially wasted magnetic field energy to the large end. This solves the overheating problem caused by simply increasing the total power, completely eliminating non-martensitic structures generated by insufficient heating at the large end. This significantly improves the hardness uniformity of the entire quenching zone and makes the hardened layer depth more consistent. The quenching inductor has a simple structure and can be directly modified from existing inductors without replacing expensive power supplies or complex program reprogramming. It is low-cost, easy to promote, and has good versatility and economy. Furthermore, this method fundamentally improves the wear resistance and contact fatigue performance of the inner ring large flange, thereby enhancing the overall service life and reliability of the bearing.

[0088] Furthermore, based on current extreme design trends, the inner ring 1 itself has a relatively small overall wall thickness, resulting in an even thinner wall at the small end of the inner ring 1. The axial width and radial height of the small flange 13 are also relatively small, with the axial direction being the axis of the ring and the radial direction perpendicular to the axial direction. During induction heating, the inductor covers the quenching surface. Under the same conditions, the small end reaches a higher temperature when the large end reaches the set temperature, making the edges or sharp corners of the small flange 13 prone to overheating. Consequently, quenching cracks are easily generated on the surface of the small flange 13 after cooling. For the thin-walled small end, sharp corners and edges will produce a "sharp corner effect," easily leading to overheating. When cooled with quenching liquid, end-face and chamfer quenching cracks are easily generated on the small end face. This paper proposes a method that fundamentally changes the thermodynamic state of the thin-walled sharp corner region, combining active heat conduction treatment and mechanical constraints to completely solve the problem of small-end cracking during induction quenching of the inner ring of tapered roller bearings.

[0089] The tapered roller bearing ring surface induction hardening device includes hardening equipment and tooling for clamping and fixing the rings, such as... Figure 8 , Figure 9 , Figure 10 As shown, the fixture includes a heat-absorbing ring 2 and a pressure block 3. The heat-absorbing ring 2 is adapted to support the inner ring 1, and the pressure block 3 is used to fix it on the heat-absorbing ring 2 and to press the inner ring 1 tightly onto the heat-absorbing ring 2. The heat-absorbing ring 2 can be installed and clamped on the worktable of the quenching equipment, and the heat-absorbing ring 2 can rotate. The quenching equipment and the quenching fixture cooperate to form a quenching device.

[0090] The quenching equipment can adopt the existing soft-strip induction quenching technology to continuously scan the quenching surface of the inner ring 1 with medium-frequency induction quenching. The sensing surfaces of the clockwise and counterclockwise scanning sensors of the quenching equipment are basically parallel and contoured to the quenching surface of the inner ring 1. The distance between the sensor and the quenching surface is maintained by the tracking device. The clockwise and counterclockwise scanning sensors scan the raceway 11 from two directions starting from the starting point and simultaneously reach the end point to complete the quenching.

[0091] Combination Figure 10 The tooling is provided with an annular heat-absorbing step surface for fitting with the small end of the ring. The annular heat-absorbing step surface has a back heat-absorbing annular surface 21 that surrounds its center line and extends along the center line direction and an end heat-absorbing annular surface 22 that is perpendicular to its center line. The back heat-absorbing annular surface 21 is used to radially correspond to the circumferential surface of the ring on the side facing away from the raceway 11. The end heat-absorbing annular surface 22 is used to contact the end face of the small end of the ring. The dimension of the back heat-absorbing annular surface 21 along the center line direction is not less than the axial width of the small flange 13 of the small end of the ring. The dimension of the end heat-absorbing annular surface 22 in the direction perpendicular to the center line is such that after the ring is installed, the small flange 13 of the small end of the ring does not protrude radially beyond the end heat-absorbing annular surface 22. During quenching, the tooling absorbs the heat at the small flange 13 of the ring.

[0092] The back heat-absorbing annular surface 21 covers the back of the small flange 13, and the end heat-absorbing annular surface 22 covers the end face of the small flange 13. The annular heat-absorbing step covers the non-quenched surface of the small end of the ring. When the surface of the small flange 13 at the small end is quenched, the tooling can absorb the heat at the small end. The excess heat accumulated in the thin-walled small end area of ​​the workpiece can be conducted away in real time by the heat-absorbing tooling through the contact interface of the tooling, thereby suppressing overheating in this area and preventing cracking during subsequent continuous cooling. It is not easy to have quenching cracks and avoid scrapping the workpiece. It is especially suitable for large-size thin-walled bearing rings.

[0093] In this embodiment, an annular heat-absorbing step surface is provided on the outer circumferential surface of the tooling for quenching the inner ring of the single-row tapered roller bearing. The circumferential surface of the ring facing away from the raceway 11 is the inner circumferential surface of the inner ring 1. In other embodiments, the annular heat-absorbing step surface can also be provided on the inner circumferential surface of the tooling for quenching the outer ring of the single-row tapered roller bearing. When used for quenching the inner ring, the ring is fitted outside the tooling; when used for quenching the outer ring, the tooling is fitted outside the ring. This tooling absorbs heat from the small end of the ring, preventing overheating of the sharp corners and edges of the small flange 13 at the small end.

[0094] The axial direction of the collar is vertical, which is also the width direction, and its radial direction is horizontal. The collar is a ring structure, and the radial dimension of the ring is the distance between its inner and outer circles, which is also the wall thickness. The larger end of the inner ring 1 is at the top, and the smaller end is at the bottom. The annular heat-absorbing step surface of the tooling is axial, with its centerline in the vertical direction.

[0095] The heat-absorbing ring 2 of the tooling is adapted to the inner ring 1. The heat-absorbing ring 2 is a circular ring used to be coaxially fitted with the inner ring 1. The annular heat-absorbing step surface is set on one side of the circumferential surface of the heat-absorbing ring 2 that is used to fit the ring, that is, on the outer circumferential surface.

[0096] The heat-absorbing ring 2 has a thinner wall at the upper end and a thicker wall at the lower end, the opposite of the bearing ring. The inner circumferential surface of the heat-absorbing ring 2 has unequal diameters axially and upward-facing steps, resulting in a thin-walled section at the upper part of the heat-absorbing ring 2 that radially corresponds to the large end of the bearing ring, while the thick-walled section at the lower part of the heat-absorbing ring 2 radially corresponds to the small end of the bearing ring. The back heat-absorbing ring surface 21 is located in the thick-walled section. The large flange 12 at the large end of the bearing ring does not contact the heat-absorbing ring 2. Using the heat-absorbing ring 2 as the mounting base for the bearing ring facilitates heat dissipation through the internal space of the heat-absorbing ring 2. This allows the thicker end to be closer to the small end of the bearing ring, and the thinner end to be closer to the large end, reducing the influence of the tooling on the temperature of the large end and improving the consistency of temperature changes between the large and small ends of the bearing ring.

[0097] exist Figure 10 In the illustrated embodiment, the inner circumferential surface of the heat-absorbing ring 2 is a stepped surface to achieve a thinner wall portion on the upper side of the back heat-absorbing ring surface 21 and a thicker wall portion where the back heat-absorbing ring surface 21 is located. In other embodiments, such as... Figure 11In one embodiment, the inner circumferential surface of the heat-absorbing ring 2 is an inner conical surface, with the larger end of the inner conical surface at the top and the smaller end at the bottom. The diameter of the central hole of the heat-absorbing ring 2 gradually decreases from top to bottom. The lower end wall thickness of the section containing the back heat-absorbing ring surface 21 of the heat-absorbing ring 2 is greater than the upper end wall thickness. The end with the larger wall thickness of the section containing the back heat-absorbing ring surface 21 of the heat-absorbing ring 2 is connected to the end heat-absorbing ring surface 22, so that the portion above the back heat-absorbing ring surface 21 has a thinner wall while the portion containing the back heat-absorbing ring surface 21 has a thicker wall. The lower end wall thickness of the section containing the back heat-absorbing ring surface 21 is not less than the upper end wall thickness. In other embodiments, such as... Figure 12 , Figure 13 In one embodiment shown, the wall thickness of the section where the back heat-absorbing ring 21 is located can be uniform, and the portion located on the upper side of the back heat-absorbing ring 21 has the same wall thickness as the portion where the back heat-absorbing ring 21 is located. The inner circumferential surface of the heat-absorbing ring 2 is a cylindrical surface.

[0098] Combination Figure 10 Continuing the explanation, the lower end wall thickness of the section containing the back heat-absorbing ring surface 21 of the heat-absorbing ring 2 is not less than the equivalent wall thickness of the collar, and the equivalent wall thickness of the collar is located at 2 / 3 of the overall inner ring width based on the small end face. The wall thickness of the portion of the heat-absorbing ring 2 below the end heat-absorbing ring surface 22 is greater than the lower end wall thickness of the section containing the back heat-absorbing ring surface 21 of the heat-absorbing ring 2. The dimension of the back heat-absorbing ring surface 21 along the centerline direction satisfies that it is not less than the distance between the cross section containing the equivalent wall thickness of the collar and the small end face. Ensuring that the back heat-absorbing ring surface 21 fully covers the back side of the small end of the collar is beneficial for improving the heat absorption effect. In other embodiments, the axial dimension of the back heat-absorbing ring surface 21 can also be greater than the axial width of the small flange but less than the distance between the cross section containing the equivalent thickness and the small end face of the collar.

[0099] The fixture has an end face opposite to the end heat-absorbing ring surface 22, which is the lower end face of the heat-absorbing ring 2. A platform is formed between this end face and the end heat-absorbing ring surface 22. The dimension of the platform along its centerline is not less than the axial width of the small flange 13 of the collar. One axial side of the platform is the end heat-absorbing ring surface 22, and the other side belongs to the lower end face of the heat-absorbing ring 2, which faces the same direction as the small end of the collar. The platform is located at the lower end of the heat-absorbing ring 2. The radial dimension of the platform is its protrusion height, and its axial dimension is its width, which is 1.5 times or more the axial width of the small flange 13. This ensures that the portion of the fixture located on the side of the small end face of the collar has sufficient width, which is beneficial for improving the heat absorption effect.

[0100] The fixture has an end peripheral surface 23 located on the side of the end heat-absorbing ring surface 22 away from the back heat-absorbing ring surface 21. The end peripheral surface 23 is also the top surface of the ring in the radially protruding direction. The end heat-absorbing ring surface 22 is in contact with the end peripheral surface 23, and the end peripheral surface 23 is in contact with the lower end surface of the heat-absorbing ring 2. The end peripheral surface 23 is flush with the outer peripheral surface of the small flange 13 after the collar is installed. By making the end peripheral surface 23 of the fixture near the small end of the collar flush with the outer peripheral surface of the small flange 13 of the small end of the collar, and by ensuring that the fixture does not protrude radially from the outer peripheral surface of the small end of the collar, interference with the inductor of the quenching equipment can be avoided. The inductor can be closer to the quenching surface of the collar, improving heating efficiency. At the same time, the outer peripheral surface of the small end of the collar does not protrude from the fixture; otherwise, cracks would occur at the outer edge of the small end of the collar during the quenching process due to high temperature and rapid cooling.

[0101] The heat-absorbing ring 2 can be divided into a main body section and an end section, which are arranged vertically. The wall thickness of the main body section is smaller than that of the end section. The upward stepped surface at the junction of the main body section and the end section forms the end heat-absorbing ring surface 22. The end peripheral surface 23 is located in the end section. The back heat-absorbing ring surface 21 and the large end mating ring surface 24 are located in the main body section. The back heat-absorbing ring surface 21 ensures that the gap between it and the peripheral surface of the ring facing away from the raceway 11 is 0.3-0.8mm after the ring is installed. This satisfies the requirement of good heat absorption while facilitating the fitting of the ring and the tooling, and also facilitates the manufacturing and processing of large-size tooling.

[0102] The back heat-absorbing annular surface 21 is an outer cylindrical surface, and the end heat-absorbing annular surface 22 is located on a plane perpendicular to the axial direction. The radial dimension of the end heat-absorbing annular surface 22 is the radial distance between its inner and outer circles. The end heat-absorbing annular surface 22 intersects the back heat-absorbing annular surface 21 perpendicularly. The radial dimension of the end heat-absorbing annular surface 22 is larger than the radial dimension of the end face of the small end of the inner ring 1, so as to ensure that there is a gap between the heat-absorbing ring 2 and the circumference of the inner ring 1, while ensuring that the end heat-absorbing annular surface 22 covers the end face of the small end of the inner ring 1 in the axial direction. In the axial projection, the projection of the end heat-absorbing annular surface 22 completely covers the projection of the end face of the small end of the inner ring 1.

[0103] The tooling has a large-end mating ring surface 24 located axially on the side of the back heat-absorbing ring surface 21 away from the end heat-absorbing ring surface 22. After the ring is installed on the tooling, the large-end mating ring surface 24 is closer to the large end of the ring than the back heat-absorbing ring surface 21, and the gap between the large-end mating ring surface 24 and the circumferential surface of the ring facing away from the raceway is greater than the gap between the back heat-absorbing ring surface 21 and the circumferential surface of the ring facing away from the raceway. That is, the outer diameter of the portion where the large-end mating ring surface 24 is located is smaller than the outer diameter of the portion where the back heat-absorbing ring surface 21 is located. The portion where the large-end mating ring surface 24 is located is located on the upper side of the back heat-absorbing ring surface 21 and radially corresponds to the large end of the ring. The large-end mating ring surface 24, the back heat-absorbing ring surface 21 of the annular heat-absorbing step surface, the end heat-absorbing ring surface 22, and the end circumferential surface 23 together constitute the outer circumferential surface of the heat-absorbing ring. The large-end mating ring surface 24 is in contact with the upper end surface of the heat-absorbing ring. While satisfying the heat absorption capacity of the tooling at the small end, reducing the heat absorption capacity of the tooling at the large end of the ring is beneficial to improving the synchronization of heating temperatures at the large and small ends of the ring. In other embodiments, the gaps between the large end mating annular surface 24 and the back heat-absorbing annular surface 21 and the inner circumferential surface of the inner ring can also be made consistent.

[0104] The fixture includes a pressure block 3 for pressing the large end of the ring to press the small end of the ring against the end heat-absorbing ring surface 22. The pressure block 3 is detachably fixed to the upper end face of the heat-absorbing ring 2. The pressure block 3 has a portion that extends radially outward from the heat-absorbing ring 2, and this portion is used to press the upper end face of the inner ring 1. Multiple pressure blocks 3 are distributed in the direction surrounding the center line of the heat-absorbing ring 2. Within the same angle range, the number of pressure blocks 3 in the quenching end area is greater than the number of pressure blocks 3 in the quenching start area. The quenching start area is the set path range that the inductor travels after it begins to rotate relative to the ring, and the quenching end area is the set path range that the inductor travels before it finishes rotating relative to the ring, which is also a set segment of the ring circumference. During continuous scanning induction quenching, the deformation of the ring will be more concentrated in the quenching end area. By setting more pressure blocks 3 in this area, a more sufficient and uniform clamping force can be provided to suppress ring deformation. At the same time, the pressure blocks 3 can ensure that the small end of the ring is in close contact with the heat-absorbing surface of the fixture, improving the heat conduction effect.

[0105] An L-shaped stepped heat-absorbing ring, made of thermally conductive steel, is used to mate with the small end of the bearing inner ring. The contact surface between the tooling and the inner ring is precision-machined to ensure a good fit with the small end face and part of the inner circumferential surface of the inner ring. The width of the stepped surface of the L-shaped heat-absorbing ring is the same as the width of the small end face, and the axial height is consistent with the axial width of the inner ring. The gap between the tooling and the workpiece contact surface is controlled at 0.3-0.8mm. The heat-absorbing ring can be analogous to a "heat sink." During quenching and heating, excess heat accumulated at the small end and sharp corners is rapidly conducted through the contact surface to the large "heat sink" tooling, thereby forcibly suppressing the temperature rise in that area, making the temperature distribution on the small end face more uniform, and effectively preventing overheating.

[0106] Simultaneously, axial pressure blocks are installed at the large end during the quenching process. Three pressure blocks are installed within the initial 600mm range at the start of quenching, one pressure block is installed at 45°, 90°, and 135°, and five pressure blocks are installed within the final 800mm range at the end of quenching. This ensures that the quenching surface of the ring workpiece remains constantly pressed against the heat-absorbing fixture throughout the entire quenching process. Excess heat accumulated in the thin-walled small end area of ​​the workpiece can be continuously conducted away by the heat-absorbing fixture through the contact interface, thereby suppressing overheating in this area and preventing cracking during subsequent continuous cooling, which would lead to the scrapping of the workpiece.

[0107] Medium carbon alloy structural steel was processed into experimental ring forgings through billet preparation, punching, ring rolling, quenching and tempering, and machining. A contour inductor was fabricated based on the shape and size of the quenching surface of the ring forging. Stepped tooling was machined from 42CrMo material according to the dimensions of the test piece. After machining, quenching was performed according to the following steps: Clean the quenched workpiece and tooling, clamp the tooling, measure the clearance between the workpiece's inner diameter and the tooling (0.5mm), install the clamping blocks, and ensure each block is firmly pressed. Perform continuous scanning medium-frequency induction hardening on the workpiece's raceway, flanges, and oil grooves at a frequency of 2.3kHz, a speed of 70mm / min, and a temperature of 880℃. Cooling is achieved using a contour-following independent water box with continuous spray cooling, employing a 19% PAG quenching fluid as the cooling medium. During quenching, two sets of inductors are used, each rotating 180° along the workpiece from the starting position and converging at the end of the quenching process. After quenching, remove the clamping blocks before tempering. After tempering, the raceway hardness is measured to be 58-63HRC, the hardened layer depth is ≥8mm, and magnetic particle inspection reveals no cracks.

[0108] The quenching method using stepped tooling for heat absorption and pressure block constraint ensures that the quenching surface of the bearing ring remains constantly pressed against the heat-absorbing tooling throughout the quenching process. Excess heat accumulated in the thin-walled small-end region of the workpiece can be continuously conducted away by the heat-absorbing tooling through the contact interface, making the cooling of the irregular cross-section more synchronous and completely solving the problem of quenching cracks at the small end of the thin-walled bearing ring.

[0109] The aforementioned surface induction hardening technology for tapered roller bearing parts can completely solve the problems of non-marginal structure and cracks on the small end face of the raceway near the large flange of the inner ring of tapered roller bearings. At the same time, it can effectively improve the uniformity of the hardened layer depth of the raceway, increase the bearing life, and adapt to induction heating of thin-walled rings of tapered roller bearings.

[0110] An embodiment of the inductor of the tapered roller bearing ring surface induction hardening device of the present invention: The inductor of the tapered roller bearing ring surface induction hardening device in this embodiment has the same structure as any of the inductors described in the embodiments of the tapered roller bearing ring surface induction hardening device described above, and will not be repeated here.

[0111] 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. An inductor for an induction hardening device for tapered roller bearing rings, characterized in that, The device includes a coil and a magnetic conductor disposed on the coil. The magnetic conductor has a large-end heating section for heating the large end of the coil and a small-end heating section for heating the small end of the coil. The cross-sectional area of ​​the large-end heating section is larger than that of the small-end heating section. The size relationship between the large-end heating section and the small-end heating section satisfies the requirement that the magnetic field strength in the large-end region of the coil is greater than that in the small-end region of the coil when the sensor is in use.

2. The inductor of the tapered roller bearing ring surface induction hardening device according to claim 1, characterized in that, The portion of the magnetic conductor located on the corresponding side of the coil has a width direction perpendicular to the side of the coil; on the same side of the coil, the width of the heating section at the large end is greater than the width of the heating section at the small end.

3. The inductor of the tapered roller bearing ring surface induction hardening device according to claim 2, characterized in that, The large end heating section has a raceway corresponding portion for corresponding to the raceway of the race ring and a large flange corresponding portion for corresponding to the inner side of the large flange of the race ring, and the width of the raceway corresponding portion is smaller than the width of the large flange corresponding portion.

4. The inductor of the induction hardening device for tapered roller bearing rings according to any one of claims 1-3, characterized in that, The cross-sectional area of ​​the large-end heating segment decreases from the direction away from the small-end heating segment to the direction closer to the small-end heating segment. The width of the end of the large-end heating segment that is connected to the small-end heating segment is smaller than the width of the end that is away from the small-end heating segment.

5. The inductor of the tapered roller bearing ring surface induction hardening device according to claim 4, characterized in that, The large-end heating section has at least two sections with different widths, wherein the section with the smallest width is connected to the small-end heating section and its width is greater than that of the small-end heating section, and the side of the large-end heating section in the width direction is a stepped surface.

6. The inductor of the tapered roller bearing ring surface induction hardening device according to claim 4, characterized in that, The width of the large-end heating section gradually decreases from the direction away from the small-end heating section to the direction closer to the small-end heating section, and the side of the large-end heating section in the width direction is an inclined surface.

7. The inductor of the induction hardening device for tapered roller bearing rings according to claim 4, characterized in that, The width of the large-end heating section gradually decreases from the direction away from the small-end heating section to the direction closer to the small-end heating section, and the side of the large-end heating section in the width direction is an arc surface.

8. The inductor of the induction hardening apparatus for tapered roller bearing rings according to any one of claims 1-3, characterized in that, The connection position between the large-end heating section and the small-end heating section is such that it radially corresponds to the equivalent wall thickness position of the collar when the sensor is in use.

9. A device for surface induction hardening of tapered roller bearing rings, characterized in that, It includes quenching equipment and tooling for clamping and fixing the races, wherein the quenching equipment includes the sensor of the tapered roller bearing race surface induction quenching device as described in any one of claims 1-8.

10. The induction hardening device for tapered roller bearing rings according to claim 9, characterized in that, The tooling is provided with an annular heat-absorbing step surface for fitting with the small end of the ferrule. The annular heat-absorbing step surface has a back heat-absorbing ring surface that surrounds its center line and extends along the center line direction, and an end heat-absorbing ring surface that is perpendicular to its center line. The back heat-absorbing ring surface is used to radially correspond to the circumferential surface of the ferrule on the side opposite to the raceway, and the end heat-absorbing ring surface is used to contact the end face of the small end of the ferrule. The dimension of the back heat-absorbing ring surface along the center line direction is not less than the axial width of the small flange of the small end of the ferrule. The dimension of the end heat-absorbing ring surface perpendicular to the center line direction is such that after the ferrule is installed, the small flange of the small end of the ferrule does not protrude radially beyond the end heat-absorbing ring surface, so that the tooling absorbs the heat at the small flange of the ferrule during quenching.

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