Effect of Gear Body Temperature on the Dynamic Characteristics of Spiral Bevel Gears

Thermal effect is an important cause of gear system engineering failure. Spiral bevel gears are widely used in helicopter transmissions, but scuffing often occurs during operation. Tooth surface body temperature is an important factor influencing scuffing in scuffing standards. A thermal dynamic model of spiral bevel gear transmission was developed based on varying tooth body temperatures under different oil spray conditions. Vibration acceleration experiments were conducted using a dedicated scuffing test rig. The results indicate that higher oil spray temperatures intensify vibrations, with a 24.3% increase in the maximum variance of vibration acceleration. Mesh frequency and stiffness decrease, increasing the likelihood of tooth surface failures such as scuffing. Accurate monitoring of tooth body temperature is critical to ensuring the reliable operation of spiral bevel gears in helicopter transmissions.