CN-122012908-A - Heat treatment method for large steel wire raceway bearing

CN122012908ACN 122012908 ACN122012908 ACN 122012908ACN-122012908-A

Abstract

A heat treatment method for a large steel wire raceway bearing relates to the technical field of heat treatment of bearings and comprises the following steps of S1, assembling an inner ring, an outer ring, two rows of steel balls and two steel wire raceways into a bearing assembly, and fixing the bearing assembly on a rolling device, wherein the two steel wire raceways are respectively clamped and fixed on the inner ring and the outer ring of the bearing assembly in a non-welding mode, each steel wire raceway is formed by bending steel wires into a ring, a reserved gap is reserved between two ends of each steel wire, and S2, at least two groups of electromagnetic induction heaters are uniformly distributed on the outer side of the circumference of the bearing assembly. According to the heat treatment method, stress slow release and heat compensation are realized through designing a special steel wire raceway structure, the problems of uneven heating, insufficient gap cooling, easy deformation and cracking and stress concentration of integral quenching of a multi-material assembly are solved, integral quenching after assembly is realized, a soft belt is eliminated from a source, and the hardness uniformity, the hardening layer consistency, the assembly precision and the service life are remarkably improved.

Inventors

CHEN ZHIYONG
CHEN LIN
LI MUYU
CHAO YUAN
ZHU XUEFENG
HOU JIAN
SHANGGUAN LINJIAN
He Dongshuai
Lai Zhangteng
CUI DI

Assignees

洛阳理工学院

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. The heat treatment method of the large steel wire raceway bearing is characterized by comprising the following steps of: S1, assembling an inner ring, an outer ring, two rows of steel balls and two steel wire raceways into a bearing assembly, and fixing the bearing assembly on a rolling device, wherein the two steel wire raceways are respectively fixed on the inner ring and the outer ring of the bearing assembly in a clamping manner in a non-welding manner, each steel wire raceway is formed by bending steel wires into a ring, and a reserved gap is reserved between two ends of each steel wire; S2, uniformly arranging at least two groups of electromagnetic induction heaters on the outer side of the circumference of the bearing assembly, starting the rolling device to enable the bearing assembly to rotate, synchronously starting the electromagnetic induction heaters, and carrying out integral induction heating on the rotating bearing assembly to a quenching temperature; In the heating process, the expansion deformation of the steel wire raceway caused by high temperature is released through the reserved gap; S3, immediately closing the electromagnetic induction heater and enabling the electromagnetic induction heater to be rapidly far away from the bearing assembly after the heating in the step S2 is completed; The lifting workbench drives the bearing assembly to be completely immersed in quenching liquid, and the bearing assembly is kept rotating in the immersing process so as to perform globally synchronous convection cooling on the bearing assembly; In the convection cooling process, the shrinkage deformation of the steel wire raceway is released through the reserved gap; S4, after the convection cooling in the step S3, tempering the bearing assembly, secondarily eliminating stress and detecting quality to obtain the bearing assembly meeting the requirements.
2. The heat treatment method for the large steel wire raceway bearing of claim 1, wherein in step S1, both ends of the steel wire are in a wedge-shaped structure.
3. The heat treatment method of the large steel wire raceway bearing of claim 1, wherein in the step S2, the number of the electromagnetic induction heaters is four, and the four electromagnetic induction heaters are uniformly distributed on the outer side of the circumference of the bearing assembly at an included angle of 90 degrees, so that 360-degree universal non-blind zone synchronous heating is realized.
4. The heat treatment method for the large steel wire raceway bearing of claim 1, wherein in the step S2, the whole body is heated to 850-900 ℃ in an induction way, and the heat is preserved for 15-25min.
5. The heat treatment method for the large steel wire raceway bearing according to claim 4, wherein in the step S2, the distance between the heating end face of the electromagnetic induction heater and the surface of the bearing assembly is 15-25mm during integral induction heating, the power of the electromagnetic induction heater of a single group is 50-80kW, and the rotating speed of the rolling device is set to be 30-60r/min.
6. The heat treatment method of the large steel wire raceway bearing of claim 1, wherein in the step S2, the surface temperature is monitored in real time through at least 8 infrared thermometers uniformly distributed in the circumferential direction of the bearing assembly, the surface temperature is controlled to be uniformly increased to 850-900 ℃, the heat is preserved for 15-25min, and the temperature fluctuation is controlled within +/-10 ℃.
7. A heat treatment method for a large steel wire raceway bearing according to claim 1, characterized in that in step S3, the bearing assembly is completely immersed in a quenching liquid in 3-5 seconds, and the rolling device is kept to operate at a rotational speed of 20-30r/min during immersion.
8. A heat treatment method for a large steel wire raceway bearing according to claim 1, characterized in that in step S3, an electromagnetic induction heater is separated from the bearing assembly at a speed of not less than 0.5m/S by a distance of not less than 100mm.
9. A heat treatment method for a large steel wire raceway bearing according to claim 1, characterized in that in step S4, the tempering treatment is carried out by heat preservation at 180-220 ℃ for 2-3h, and then cooling with a furnace.
10. The heat treatment method for the large steel wire raceway bearing of claim 1, wherein in step S4, after tempering treatment is completed, a steel wire raceway of the bearing assembly is removed, secondary elimination of residual stress of the bearing assembly is achieved, and then the steel wire raceway is clamped to the inner ring and the outer ring again.

Description

Heat treatment method for large steel wire raceway bearing Technical Field The invention relates to the technical field of bearing heat treatment, in particular to a heat treatment method for a large steel wire raceway bearing. Background The main bearing of the steel wire raceway for the CT machine is a core bearing component of a rotary scanning system and is used for connecting a fixed frame and a rotary scanning mechanism, axial, radial and overturning moment compound loads are required to be born, and the performance of the main bearing directly determines the scanning precision and the running stability of the CT machine. The bearing generally comprises an inner ring, an outer ring, two rows of steel balls which are circumferentially distributed, an outer steel wire raceway and an inner steel wire raceway, wherein the diameter is generally 2m-5m, and in the production process of the large steel wire raceway bearing, a heat treatment process is a key link for improving the mechanical property of the bearing, wherein the hardness, the wear resistance and the shock resistance of the bearing are directly affected by quenching treatment, and meanwhile, the scanning precision, the running stability and the service life of a CT machine are also determined by quenching quality. The prior art has the following defects which cannot be overcome: The step quenching process has the defects that the traditional process is used for assembling after quenching the steel wire raceway, the inner ring and the outer ring respectively, a plurality of sets of tools and a plurality of times of heating are needed, the process is complicated, the energy consumption is high, the period is long, the component quenching residual stress is released during the assembly, the coaxiality deviation is easy to generate, and the assembly precision and the operation stability are reduced. The soft belt which cannot be eliminated exists in the open-loop rotary quenching, namely, a dead zone which is not heated is reserved in the single-inductor scanning heating process, namely, the soft belt is low in hardness and poor in impact resistance, the soft belt becomes a weak point of a bearing, and the whole bearing capacity and the safety reliability are seriously reduced. In summary, the prior art cannot simultaneously meet the requirements of integrated quenching, no soft belt, uniform cooling in the whole area and high hardness uniformity of the assembly, and cannot solve the problems of stress concentration and heat non-uniformity caused by integrated quenching, so that the main bearing of the CT machine is difficult to adapt to the use requirements of high precision, high reliability and long service life. Disclosure of Invention The invention aims to provide a heat treatment method for a large steel wire raceway bearing, which realizes stress slow release and heat compensation by designing a special steel wire raceway structure, solves the problems of uneven heating, insufficient gap cooling, easy deformation and cracking and stress concentration of integral quenching of a multi-material assembly, realizes integral quenching after assembly, eliminates a soft belt from a source, and remarkably improves hardness uniformity, hardening layer consistency, assembly precision and service life. The technical scheme adopted by the invention is that the heat treatment method of the large steel wire raceway bearing comprises the following steps: S1, assembling an inner ring, an outer ring, two rows of steel balls and two steel wire raceways into a bearing assembly, and fixing the bearing assembly on a rolling device, wherein the two steel wire raceways are respectively fixed on the inner ring and the outer ring of the bearing assembly in a clamping manner in a non-welding manner, each steel wire raceway is formed by bending steel wires into a ring, and a reserved gap is reserved between two ends of each steel wire; S2, uniformly arranging at least two groups of electromagnetic induction heaters on the outer side of the circumference of the bearing assembly, starting the rolling device to enable the bearing assembly to rotate, synchronously starting the electromagnetic induction heaters, and carrying out integral induction heating on the rotating bearing assembly to a quenching temperature; In the heating process, the expansion deformation of the steel wire raceway caused by high temperature is released through the reserved gap; S3, immediately closing the electromagnetic induction heater and enabling the electromagnetic induction heater to be rapidly far away from the bearing assembly after the heating in the step S2 is completed; The lifting workbench drives the bearing assembly to be completely immersed in quenching liquid, and the bearing assembly is kept rotating in the immersing process so as to perform globally synchronous convection cooling on the bearing assembly; In the convection cooling process, the shrinkage deformation of the steel wire