For the involute gear, the tooth profile parameters are mainly the number of teeth Z, modulus, pressure angle α, modification coefficient X, addendum height coefficient h and tip clearance coefficient. Because the influence of trapped oil on the average flow rate and pulsation is mainly reflected in the axial gap, the influence of tooth profile parameters on the theoretical and actual flow is consistent.
From the formula, through a series of detailed derivation, it is concluded that:
From this, we can calculate the specific influence of the tooth profile parameters on the actual mean value and pulsation coefficient. The coefficient of top clearance has no effect. The larger the modulus is, the greater the mean value is, but the pulsation coefficient remains unchanged; the more teeth are, the greater the mean value is, the smaller the pulsation coefficient is, and the more obvious the effect is; the greater the pressure angle or the tooth top height coefficient is, the greater the mean value is, but the greater the pulsation coefficient is; the larger the modification coefficient is, the smaller the mean value is, but the greater the pulsation coefficient is. Therefore, the combination of small modulus and large number of teeth can be used to improve the mean value and pulse.