Manufacturing method of precise tapered roller specially for high speed train unit

Abstract

The invention discloses a manufacturing method of a precise tapered roller specially for a high speed train unit. The manufacturing method comprises the processes of high-speed multistation cold-forging molding, hot acid pickling, stress-relieving annealing, pre-cleaning, quenching treatment, low-temperature cold treatment, first tempering, grinding, magnetic powder inspection, superfinishing, cleaning, finished product appearance inspection, size sorting, spot checking for surface quality, oiling, counting and packaging. The high-speed multistation cold-forging molding process is adopted to realize direct heat treatment on a forged piece, the incomplete quenching process is adopted to carry out hot quenching treatment under the protection of controllable atmosphere, low-temperature cold treatment is carried out immediately after quenching treatment, after the temperature of a steel ball after cold treatment is restored to be at room temperature, the first tempering treatment is carried out, a ball grinding cardinal plane during grinding is in a non-magnetic mode, and all related processes of grinding processing after quenching can be carried out one time. By adopting the manufacturing method, the service life of a roller can be prolonged, the material consumption and the production cost are reduced, the quality of a roller blank is improved, the processing flows of the roller are reduced and the production efficiency is improved.

Description

[0001] technical field [0002] The invention relates to a method for manufacturing a tapered roller for a high-speed EMU bearing, in particular to a method for manufacturing a special precision tapered roller for a high-speed EMU. Background technique [0003] Compared with the reality that my country already has independent intellectual property rights of high-speed EMU technology, the localization application of supporting bearings is still blank, which is a shortcoming for the equipment manufacturing industry that is striving for high-end equipment. [0004] At present, most high-speed trains are fully electrified EMUs. The input shaft speed of the EMU gearbox is very high, up to 6000 r / min, and the input shaft bearing design must be suitable for this high speed. Therefore, the input shaft of the gearbox mainly uses ball bearings and tapered roller bearings. [0005] In addition to supporting the static and dynamic radial loads formed by the weight of the train and the...

AI Technical Summary

Problems solved by technology

[0009] 1) At present, the raw material of precision tapered rollers for railway freight in the domestic market is ordinary GCr15 bearing steel, and the oxygen content is 8-12PPM. The material quality is poor, the oxygen content is high, and there are many inclusions. Low, in the roller blank forming process, low-speed stamping is directly used, and the raw material is made into a conical ring-shaped roller blank with a boss at the small end and a large discrete size roller blank by the open cutting method. The molding quality is unstable, and the roller blank ring is large, the material loss is large, the frequency of mold replacement is high, and the production cost is high;

[0010] 2) The traditional heat treatment quenching and tempering process cannot improve the plasticity of the material and change the multiple superimposed grinding stress states, making the product prone to early fatigue, peeling, and even cracking;

[0011] 3) The traditional roller heat treatment does not have an ultra-low temperature cold treatment process, and the grinding of the spherical base surface also adopts a magnetic grinding method. The internal stress of the roller cannot be completely eliminated, and early fatigue is prone to occur, and the processing accuracy is not high