Tapered roller bearing and method for manufacturing the same

Abstract

The application discloses a kind of tapered roller bearing and its preparation process, including bearing inner ring, bearing outer ring, roller and cage, bearing inner ring is made of carburizing steel material, bearing outer ring is made of carburizing steel or high-carbon chromium bearing steel material, bearing inner ring outer wall and bearing outer ring inner wall are all provided with raceway, bearing inner ring and bearing outer ring are all processed by heat treatment process to make raceway surface form carbon potential layer, further including a preparation process, including following flow: S1, after cutting seamless steel tube, it is prepared into bearing outer ring and bearing inner ring by cold extrusion molding;S2, bearing outer ring is processed by heat treatment;S3, bearing inner ring is processed using carburizing heat treatment process and cold treatment process.The application solves the problems that traditional tapered roller bearing inner and outer ring material adaptability is poor, raceway wear resistance and strength performance are uneven, bearing is easy to appear wear deformation and fatigue failure when serving, and the overall heat treatment process lacks pertinence.

Description

Technical Field

[0001] This invention relates to the field of bearing technology, specifically to a tapered roller bearing and its manufacturing process. Background Technology

[0002] Tapered roller bearings, as an important type of rolling bearing, are widely used in automobiles, construction machinery, machine tools, mining machinery and other fields due to their ability to withstand radial and axial loads simultaneously, high load-bearing capacity and high limiting speed. Their performance directly affects the operational stability, reliability and service life of the entire equipment.

[0003] In existing technologies, the selection of materials and heat treatment processes for the inner and outer rings, rollers, and cages of tapered roller bearings often lack specificity, leading to numerous technical defects in actual service. On the one hand, some bearings use a single material for both the inner and outer rings, failing to select suitable materials based on their stress characteristics and operational requirements. This makes it difficult to achieve a balance between wear resistance, strength, and toughness in both the inner and outer rings, easily resulting in raceway wear, spalling, cracks, and other failures. On the other hand, existing heat treatment processes mostly adopt a uniform approach, without designing specific heat treatment solutions for the material differences between the inner and outer rings and their operational stress conditions. This results in an unreasonable carbon potential layer depth on the raceway surface, failing to effectively improve the raceway's hardness, wear resistance, and fatigue resistance, thereby shortening the bearing's service life.

[0004] Meanwhile, the existing tapered roller bearings lack precise control over the raceway convexity and roller outer surface convexity design. Unreasonable convexity values ​​can easily lead to uneven stress during bearing operation, generating additional stress, aggravating local wear, and reducing the bearing's operational stability. In addition, improper selection of roller materials and rudimentary cage processing technology further affect the overall structural strength and operational flexibility of the bearing, making it prone to failure under heavy load, high speed, and harsh operating conditions, and unable to meet the requirements of modern equipment for high reliability, long service life, and high load-bearing capacity of bearings. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a tapered roller bearing and its manufacturing process, which solves the problems of poor material compatibility between inner and outer rings, uneven wear resistance and strength properties of raceways, easy wear deformation and fatigue failure during bearing service, and insufficient overall heat treatment process in traditional tapered roller bearings.

[0006] To achieve the above objectives, the present invention provides a tapered roller bearing, comprising an inner bearing ring, an outer bearing ring, rollers, and a cage. The inner bearing ring is made of carburized steel, and the outer bearing ring is made of carburized steel or high-carbon chromium bearing steel. Both the outer peripheral wall of the inner bearing ring and the inner peripheral wall of the outer bearing ring are provided with raceways. Both the inner and outer bearing rings are heat-treated to form a carbon potential layer on the raceway surface.

[0007] The advantages of adopting the above technical solution are as follows: The bearing inner ring is made of carburized steel, which significantly improves its strength, hardness, and wear resistance, adapting to the stress requirements during operation. The bearing outer ring is made of carburized steel or high-carbon chromium bearing steel, balancing material compatibility and application flexibility. Appropriate materials can be selected based on actual service conditions, ensuring the stability and durability of the outer ring structure. Both the outer and inner circumferential walls of the inner and outer rings have raceways, providing a stable rolling trajectory for the rollers, reducing roller offset and friction during movement, and improving the overall smoothness of bearing operation. Furthermore, both the inner and outer rings undergo heat treatment processes to form a carbon potential layer on the raceway surface, further enhancing raceway surface properties, improving fatigue and wear resistance, extending the overall service life of the bearing, ensuring stable operation of the bearing under various working conditions, and improving the bearing's reliability and adaptability.

[0008] The present invention further specifies that the depth of the carbon potential layer ranges from 0.35 to 2.6 mm.

[0009] The advantages of adopting the above technical solution are as follows: Setting the carbon potential layer depth in this technology allows for a good match between the surface hardness of the raceway and the toughness of the core, preventing insufficient wear resistance and easy wear and peeling due to an excessively shallow carbon potential layer, while also preventing increased brittleness and cracking due to an excessively deep carbon potential layer, thus ensuring the integrity and stability of the raceway structure. Furthermore, by precisely controlling the carbon potential layer depth, the overall mechanical properties of the inner and outer rings can be optimized, improving the raceway's fatigue resistance and load-bearing capacity, ensuring that the bearing is less prone to failure during long-term service, extending its service life, adapting to different operating conditions, and improving the overall performance and reliability of the bearing.

[0010] The invention further comprises: the roller is made of high carbon chromium bearing steel, and the cage is made of sheet metal by stamping.

[0011] The advantages of adopting the above technical solution are: the rollers are made of high-carbon chromium bearing steel, which can effectively improve the hardness, wear resistance and deformation resistance of the rollers, adapt to the radial and axial loads borne by the rollers during rolling, reduce roller surface wear and deformation, and ensure the rolling accuracy of the rollers; while the cage is made of sheet metal stamping, which can realize the mass production of the cage, reduce processing costs, and at the same time ensure the structural dimensional accuracy and structural strength of the cage.

[0012] The present invention further specifies that the raceway convexity value of the outer ring of the bearing is in the range of 2-9 μm, the raceway convexity value of the inner ring of the bearing is in the range of 5-15 μm, and the outer surface convexity value of the roller is in the range of 1-10 μm.

[0013] The advantages of adopting the above technical solution are as follows: setting the convexity of the bearing outer ring, inner ring raceway, and outer surface of the rollers can optimize the internal force distribution of the bearing, reduce the additional stress caused by uneven force during operation, and avoid the aggravation of raceway or roller wear caused by local stress concentration; moreover, the reasonable design of the convexity can improve the contact accuracy between the roller and the raceway, reduce contact friction loss, reduce bearing operating noise, and enhance the bearing's impact resistance, avoid local wear and spalling caused by point contact between the roller and the raceway, ensure the stable operation of the bearing under high-speed and heavy-load conditions, extend the bearing service life, and improve the bearing's operational stability and reliability.

[0014] This invention provides a manufacturing process for tapered roller bearings, comprising the following steps: S1. Seamless steel pipes are cut and then cold-extruded to form the outer ring and inner ring of the bearing. S2. The outer ring of the bearing is heat-treated by integral martensitic quenching, carbonitriding heat treatment, or induction hardening. S3. The inner ring of the bearing is processed using carburizing heat treatment and cold treatment processes.

[0015] The present invention further specifies that the carburizing heat treatment temperature range in step S3 is 930-1000°C, and the proportion of high carbon potential in the carburizing heat treatment is 1.2-1.6%.

[0016] The present invention further specifies that the temperature range of the cold treatment process in step S3 is -40 to -80°C.

[0017] The advantages of adopting the above technical solution are as follows: In step S1, the bearing inner and outer rings are prepared by cold extrusion molding after cutting seamless steel pipes, which can effectively preserve the mechanical properties of the material itself, reduce material damage during processing, and improve the dimensional accuracy and forming quality of the inner and outer rings. At the same time, the cold extrusion molding process can realize mass production, improve production efficiency, and reduce processing costs. In step S2, multiple heat treatment methods are designed for the bearing outer ring, which can be flexibly selected according to the outer ring material and actual operating conditions to ensure the heat treatment effect of the outer ring and strengthen the structural strength and wear resistance of the outer ring. In step S3, the bearing inner ring is processed by a combination of carburizing and cold treatment processes. This process can precisely optimize the mechanical properties of the inner ring, improving its hardness, wear resistance, and fatigue resistance. By rationally controlling the carburizing heat treatment temperature and the proportion of high carbon potential, the formation effect of the carbon potential layer on the inner ring raceway can be ensured, guaranteeing the performance matching between the carbon potential layer and the inner ring core. The aforementioned precise control of the cold treatment process temperature can effectively reduce residual austenite in the inner ring, improving the dimensional stability and structural toughness of the inner ring and preventing deformation during use. The aforementioned overall manufacturing process is highly targeted and has a smooth flow, which can significantly improve the overall performance and service life of the bearing, ensuring stable operation of the bearing under various working conditions, while improving production efficiency, reducing production costs, and adapting to the needs of large-scale production. Attached Figure Description

[0018] Figure 1 This is a partial cross-sectional view of the present invention; Figure 2 for Figure 1 A schematic diagram of the carbon potential layer. Detailed Implementation

[0019] This invention provides a tapered roller bearing, comprising an inner ring 1, an outer ring 2, rollers 3, and a cage 4. The inner ring 1 is made of carburized steel, and the outer ring 2 is made of carburized steel or high-carbon chromium bearing steel. Both the outer and inner peripheral walls of the inner ring 1 and the outer ring 2 are provided with raceways 11. Both the inner and outer rings are heat-treated to form a carbon potential layer 12 on the surface of the raceway 11, with a depth ranging from 0.35 to 2.6 mm. The rollers 3 are made of high-carbon chromium bearing steel, and the cage 4 is formed by stamping sheet metal. The convexity of the raceway 11 of the outer ring 2 ranges from 2 to 9 μm, the convexity of the raceway 11 of the inner ring 1 ranges from 5 to 15 μm, and the convexity of the outer surface of the rollers 3 ranges from 1 to 10 μm.

[0020] This invention provides a manufacturing process for tapered roller bearings, comprising the following steps: S1. Seamless steel pipes are cut and then cold-extruded to form the outer ring and inner ring of the bearing. S2. The outer ring of the bearing is heat-treated by integral martensitic quenching, carbonitriding heat treatment, or induction hardening. S3. The inner ring of the bearing is processed using carburizing heat treatment and cold treatment processes.

[0021] Furthermore, in step S3, the carburizing heat treatment temperature range is 930-1000°C, and the proportion of high carbon potential in the carburizing heat treatment is 1.2-1.6%.

[0022] Furthermore, the temperature range of the cold treatment process in step S3 is -40 to -80°C.

[0023] The aforementioned technologies employ three different processing methods for the bearing outer ring: integral martensitic hardening, carbonitriding heat treatment, or induction hardening. These methods allow for flexible adaptation based on the outer ring material and actual service conditions, each offering significant advantages: integral martensitic hardening effectively enhances the overall hardness and structural strength of the bearing outer ring, strengthens its wear resistance and deformation resistance, and is suitable for heavy-load, high-wear-resistance applications, ensuring the structural stability of the outer ring during long-term service; while carbonitriding heat treatment forms a uniform carbonitride compound layer on the bearing outer ring surface, balancing surface hardness and core toughness. Improving the fatigue resistance and corrosion resistance of the outer ring reduces wear, spalling, and other failures during service, extending the service life of the outer ring. Induction hardening offers rapid heating and high efficiency, allowing for precise control of the hardening zone and preventing overall deformation of the outer ring due to heat, thus ensuring dimensional accuracy. It also quickly increases the hardness of the hardened area, making it suitable for applications with high requirements for dimensional accuracy and surface hardness. Furthermore, it has low energy consumption and is suitable for large-scale production. These three processes complement each other, fully meeting the performance requirements of bearing outer rings in different scenarios and improving the overall adaptability and reliability of the bearing.

[0024] The foregoing has shown and described the basic principles and main features of the present invention, as well as its advantages. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A tapered roller bearing, characterized in that: The bearing includes an inner ring, an outer ring, rollers, and a cage. The inner ring is made of carburized steel, and the outer ring is made of carburized steel or high-carbon chromium bearing steel. Both the outer and inner walls of the inner and outer rings are provided with raceways. Both the inner and outer rings are heat-treated to form a carbon potential layer on the raceway surface.

2. A tapered roller bearing according to claim 1, characterized in that: The depth of the carbon potential layer ranges from 0.35 to 2.6 mm.

3. A tapered roller bearing according to claim 1, characterized in that: The rollers are made of high-carbon chromium bearing steel, and the cage is made of sheet metal by stamping.

4. A tapered roller bearing according to claim 1, characterized in that: The raceway convexity of the outer ring of the bearing ranges from 2 to 9 μm, the raceway convexity of the inner ring of the bearing ranges from 5 to 15 μm, and the outer surface convexity of the roller ranges from 1 to 10 μm.

5. A manufacturing process for the tapered roller bearing according to any one of claims 1-4, characterized in that: The process includes the following steps: S1. Seamless steel pipes are cut and then cold-extruded to form the outer ring and inner ring of the bearing. S2. The outer ring of the bearing is heat-treated by integral martensitic quenching, carbonitriding heat treatment, or induction hardening. S3. The inner ring of the bearing is processed using carburizing heat treatment and cold treatment processes.

6. The preparation process according to claim 5, characterized in that: In step S3, the carburizing heat treatment temperature range is 930-1000°C, and the proportion of high carbon potential in the carburizing heat treatment is 1.2-1.6%.

7. The preparation process according to claim 5, characterized in that: The temperature range for the cold treatment process in step S3 is -40 to -80°C.

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