According to the transmission principle of two-tooth difference swing movable teeth transmission, the force analysis of two-tooth difference swing movable teeth transmission was carried out. It was found that the normal distortions of contact points of the swing movable teeth along with the surge wheel submit to sine distribution. The explicit calculation formulae of the forces were derived, which were acted on the main parts of the transmission: swing movable teeth，the surge wheel，movable tooth spar pegs，and the internal gear. The method of strength calculation of two-tooth difference swing movable teeth transmission was put forward.Aiming at the main failure forms of two-tooth difference swing movable teeth transmission, based on the Hertz theory of elasticity mechanics, the calculation formulas of contact fatigue strength for meshing pairs between swing movable teeth and the surge wheel, meshing pairs between swing movable teeth and the internal gear in two-tooth difference swing movable teeth transmission were derived. The method to compute bending strength of the movable tooth spar peg in two-tooth difference swing movable teeth transmission was investigated. And the corresponding calculation formulae were derived. A numerical example was given for illustration.The results showed that above-mentioned calculation formulas of forces and strength are correct.The research results can be used as a theoretical basis for the design of two-tooth difference swing movable teeth transmission.
