CPC F16H 57/031 (2013.01) [B23K 33/006 (2013.01); B23K 26/28 (2013.01); B23K 37/06 (2013.01); F16H 2057/02008 (2013.01); F16H 2057/02017 (2013.01)] | 7 Claims |
1. A transmission gear box comprising:
a cylindrical box body, the box body having an axis therethrough and defining a cavity for gears;
an end cover fixed on at least one axially opened end of the cavity of the box body; and
a fitting structure extending at least in an axial direction of the box body and the end cover, the fitting structure including an inner fitting surface located on a surface of one of the box body and the end cover, and an outer fitting surface located on a surface of the other one of the box body and the end cover,
wherein a clearance fit area having interference fit areas located on both sides thereof is arranged between the inner fitting surface and the outer fitting surface, the inner fitting surface including a stepped inner rib having three steps extending circumferentially and the outer fitting surface including a stepped outer rib having two steps extending circumferentially such that one interference fit area of the interference fit areas is at a different radial distance than the other interference fit area of the interference fit areas and a molten body produced by melting of an interference fit area occupies a portion of the clearance fit area.
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