Effects of centring error and angular misalignment on crack initiation life in herringbone gears.

• Crack initiation life model of herringbone gear is proposed by critical plane method. • Centring error and angular misalignment sharply reduce the crack initiation life. • Moderate tip relief can eliminate stress concentration and extend the gear life. • Angular adjustment balances the load in centring error gears, improving gear life. The effects of centring error and angular misalignment on crack initiation life in herringbone gears are investigated in this work. Herringbone gears with centring error or angular misalignment are modelled for contact analysis. A crack initiation life model of standard and error gears is proposed in accordance with tooth stress history and a critical plane method for nonproportional loading. Then, the effects of centring error and angular misalignment on crack initiation life in herringbone gears are investigated. Results show that centring error and angular misalignment sharply reduce crack initiation life, but a moderate tip relief can eliminate stress concentration and extend crack initiation life. Furthermore, angular adjustment balances the load distribution of the left and right teeth in herringbone gears with centring error, improving tooth crack initiation life. [ABSTRACT FROM AUTHOR]