Research on characteristics of gear knocking under no-load condition

To simulate the no-load knocking characteristics of gears, an angular acceleration excitation is applied in the torsional direction of the active gear.

Where A is the amplitude of the angular acceleration excitation and Fe is the frequency of the angular acceleration excitation.

No-load speed is 1000 r/min, and angular acceleration excitation amplitude and frequency are 1000rad/s2 and 60Hz respectively.The time-domain and frequency-domain curves of gear meshing force are shown in the figure. It can be seen that there is double-sided impact on the gear. The engagement state of tooth surface and tooth back alternates. Among them, the engagement force greater than 0 is the engagement state of tooth surface and the engagement force less than 0 is the tooth back.

In meshing state, the meshing force equal to 0 is tooth removal state.During the transition process when the meshing state changes, the two gears undergo multiple impacts to achieve the transition. This is because the first impact energy is not enough to directly reverse the impact of the gears, but multiple impacts are required to achieve the transition, and there is a short time of tooth shedding during the transition.

It can be seen from the spectrum that the frequency components of meshing force are mainly external excitation frequency and odd multiple frequency. At the same time, a continuous spectrum [0,5000Hz] appears in a wide frequency range.Among them, the corresponding amplitude of external excitation frequency reaches the maximum 4570N.