In order to study the vibration characteristics of single-stagetransmission system under meshing impact excitation, the obtained meshing impact curve is input into the dynamic equations of single-stage helical gear transmission, and the vibration response of single-stage helical gear transmission system with input torque of 80N · m, 100N · m and 120N · m is obtained, and the vibration speed diagram as shown in Fig. 1 is drawn.
Figure 1 shows the vibration speed diagram of single-stage helical gear transmission under three different loads when meshing impact is separately excited. It can be seen from the figure that: under the condition of meshing impact single excitation, the resonance speeds of 1 / 3 and 1 / 2 are the same In the non resonant region, the gear vibration increases with the increase of the rotating speed; in the over resonance region, the influence of the rotational speed on the vibration characteristics of the system is obvious. This is because the meshing impact force increases with the increase of rotating speed, and the growth trend is approximately linear, which is consistent with the conclusion in the gear manual that the dynamic load coefficient increases with the increase of gear pitch speed.
In order to study the time-domain and frequency-domain characteristics of helical gear transmission under meshing impact single excitation, the time-domain diagrams of the system at different speeds are shown in Fig. 2 and Fig. 3.
It can be seen from Fig. 2 that the main feature of meshing into impact area is the sudden change of the negative direction of the system vibration acceleration; this is because in the gear meshing into the impact area, the speed of the driven wheel will rise sharply, and according to the formula, the relative vibration acceleration in the meshing line direction of the gear end face will decrease sharply. In the figure, TZ is a meshing period. After the meshing impact is formed, the vibration acceleration of the system will gradually attenuate with TD as the period, and 1 / TD is the natural frequency of the system; because there are many high-frequency components in the meshing impact excitation, the vibration acceleration of the system also attenuates rapidly. With the increase of rotating speed, the meshing period TS / M (/ degree speed) and the square line meshing TZ of vibration direction also decrease. When the meshing period TZ is the same as the vibration acceleration attenuation period TD, the system will resonate. As shown in Fig. 3, the 8900rpm time domain diagram under meshing impact excitation, where 8900rpm is the resonance speed of single-stage helical gear transmission.