The invention discloses a method for
machining a large inner gear ring of a wind
turbine gear box. The method includes the steps that 1, an inner gear ring blank is formed in a
forging forming mode according to the specification and
forging standard of the inner gear ring; 2, outer circle rough
machining, inner hole rough
machining and end face rough machining are conducted on the inner gear ring blank, the outer circle, an inner hole and an end face are primarily formed, and allowance is reserved; 3, rough machining is conducted on the inner gear ring obtained after outer circle rough machining, inner hole rough machining and end face rough machining are conducted to enable the inner gear ring to be in a tooth shape; 4,
quenching and
tempering are conducted on the tooth-shaped inner gear ring obtained after rough machining is conducted; 5, the profile and the inner hole of the inner gear ring obtained after
quenching and
tempering are machined through finish machining; 6,
nitrogen treatment is conducted on the inner gear ring obtained after finishing machining is conducted. By means of the method for machining the large inner gear ring of the wind
turbine gear box,
quenching and
tempering are conducted on the inner gear ring which is machined to be in the tooth shape through rough machining, the quenching and tempering effects on the tooth top, the
tooth root and the
tooth surface are the same, the uneven quenching and tempering effect caused by the limited quenching and tempering
hardenability is avoided, and the comprehensive mechanical performance of the interior of the inner gear ring is improved; meanwhile, working allowance of follow-up finishing machining is lowered, and
machining deformation is reduced.