The calculation equation of the gear supports reaction was deduced under the action of sliding friction between teeth
by fully analyzing the forces exerted on the driving gear of reducing-speed asymmetric spur gear drive system with double pressure angles in the single and double gears meshing range.And
the evaluation indexes of gear supports reaction fluctuation in the condition of the random interteeth load were presented.Simulation indicates that the friction between teeth is one of influential factors to the gear supports reaction fluctuation
and the effective measures to decrease the fluctuation range of gear supports reaction include:improve the precision of gear face
lubricate reasonably
decrease the pressure angle and increase the gear number.