Heat Treatment Process Check for Staggered Helical Gear Fault

The driving wheel of the staggered helical gear is made of 42Cr Mo, conditioned and tempered, while the driven wheel is made of ZCu Sn10P1 and cast in sand.As can be seen from the picture taken in disassembly, the tooth surface of driven gear is seriously worn and the tooth surface of active gear is also marked with wear.There is no obvious wear on the tooth surface of the prototype structure after long-term test and operation examination.The structure of the drive is consistent with that of the parent type. Installation and injection of staggered helical gears meet the design requirements and are consistent with that of the parent type.

The tooth profile parameters and material composition of staggered helical gear mothers were also checked in the previous design process, but the heat treatment process was not checked.Therefore, under the condition that the structural parameters, installation, injection and other elements meet the design requirements, the wear of this staggered helical gear is probably caused by different heat treatment processes.

After wear of staggered helical gear, check the hardness and heat treatment process of the parent structure staggered helical gear.

The hardness of the tooth surface of the parent staggered helical gear is significantly higher than that of the transmission structure. Referring to relevant literatures, it can be seen that improving the hardness of the tooth surface can greatly improve the wear life of the gear tooth surface.The hardness of the tooth surface of the cross-drive helical gear is low, and the contact stress of the tooth surface may have exceeded the allowable fatigue contact stress during meshing, resulting in tooth surface wear.