Abstract:

For the engineering gear with the pitch deviation, vibration characteristics of a gear rotor system with the pitch deviation are studied. A model is introduced for analyzing the influence of pitch deviation on the gear mesh stiffness and no load transmission error. Based on this model, a general gear dynamic model is developed. Combined this model with the rotor system model, a finite element model of the gear rotor system is established. Then considering the effects of the tooth pitch deviation, vibration characteristics of a spur gear rotor system are analyzed. The results showed that the gear mesh stiffness of double teeth meshing area decreases and no load transmission error increases considering the pitch deviation. What’s more, the vibration of gear system increases and the side bands of mesh frequency and higher-order harmonics can be found with the pitch deviation. Those side bands are mainly composed of driving and driven gear rotational frequencies and multiple-frequencies of rotational frequencies. The amplitudes of the side bands can be decreased by the less pitch deviation and bigger torque.

Key words: mesh stiffness, rotor system, spur gear, vibration characteristics, pitch deviation