A mathematics analytic model of a motor in wheel transmission system is set up by using the finite element theory.The tooth force of the helical gear on load in the transmission is analyzed.By means of wireless telemetering the dynamic tooth stress of a developed motor in wheel transmission is tested.The study shows the law of the root stress changing in various speed.The optimum speed
the transmission speed with the hightest mechnical efficiency
is obtained.And based on the test results
a rational method to improve the processing technology of a motor in wheel system is presented.