Scope of application: conventional gear used on reducer; among them, thin wheel is not applicable to this standard, and the diameter / thickness of thin wheel is ≥ 8

Rough turning allowance standard of keyed gear

1.Inner hole size (mm)

a) Inner hole diameter = (nominal value of inner hole – 2 * h) ± 0.1

b) Where h = CHD + 0.4, CHD (or EHT) is the nominal value of the thickness of the heat treated carburized layer indicated on the drawing.

c) The retention of inner hole shall be related to whether the hardness after heat is required in the drawing. If the hardness is not required after heat of inner hole, the retention before heat shall be greater than the effective carburizing layer. If the hardness is required after heat of inner hole, the retention before heat shall be adjusted.

2.Inner ring end face size (mm)

a) Inner ring thickness = (nominal thickness + 2 * h) ± 0.1, with uniform allowance on both sides.

b) Where h = CHD + 0.4, CHD (or EHT) is the nominal value of the thickness of the heat treated carburized layer indicated on the drawing.

3.Outer ring end face size (mm)

a) The thickness of outer ring = nominal thickness + 0.3 ~ 0.5, and the allowance is left on the base surface side; the tolerance shall comply with the tolerance requirements of the original drawing

4.Chamfer of inner hole

a) Inner hole blunt 0.2 ~ 0.5 * 45 °