Processing method for reducing carburizing and quenching deformation of helical gear

Abstract

The invention provides a processing method for reducing the carburizing and quenching deformation of a helical gear. The method includes the following steps that a helix angle variable beta' for reverse deformation is reserved for helix gear machining before carburizing and quenching of the gear, that is to say, the machining helix angle of the helical gear before the carburizing and quenching process is equal to a value obtained by subtracting the helix angle margin beta' for revere deformation on the basis of a design helix angle beta; the helix angle variable beta' is set according to the design helix angle beta of the gear, the tooth-direction effective analysis range H of the gear and a tooth-direction heat treatment deformation amount M in the gear hobbing or gear shaping process. Inthe method, based on the reverse deformation rule, the distortion generated by heat treatment is offset by the helix angle variable. The helix angle meets process requirements after carburizing and quenching of the gear, it is guranateed that the upper and lower section deformation will not be out of tolerance after carburizing and quenching in subsequent finish machining of the tooth-direction gear, the workload of subsequent finish machining is reduced, and the cutting amount of a carburized layer is reduced.

Description

technical field [0001] The invention relates to a processing method of helical gears, in particular to a processing method for reducing carburizing and quenching deformation of helical gears, and belongs to the technical field of gear processing. Background technique [0002] Helical gears usually use rough machining methods such as hobbing, milling, and shaping. The finishing of the gear teeth adopts fine grinding teeth to ensure the precision requirements of the gears. After carburizing and quenching of the gear, a carburized layer with high hardness and wear resistance is formed on the surface. The overall quenching of the core has high strength and impact toughness. After the overall carburizing and quenching of the gear, it has excellent comprehensive mechanical properties. [0003] The carburizing and quenching process has slow heating, long production cycle and high cost. Since the helical gear is kept at a high temperature of about 900~950°C for a long time, the ri...

AI Technical Summary

Problems solved by technology

Since the helical gear is exposed to high temperatures of around 900~950°C for a long time, the rigidity of the gear is reduced, and the deformation of the gear teeth cannot be controlled during the long-term heat treatment process, resulting in large distortion at high temperatures, resulting in the layer depth of the gear teeth after subsequent processing. Unevenness, large hardness deviation, or even excessive deformation, resulting in black skin that greatly increases the amount of grinding, resulting in higher grinding costs and even scrapping due to excessive deformation of the tooth surface that cannot meet the requirements

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