Based on the dynamic theory of rolling bearings

the dynamic differential equations and the friction torque mathematic models of double-row spherical roller bearings were established. GSTIFF (gear stiff) integer algorithm with variable steps was used to solve the equations. The influences on friction torque of double-row spherical roller bearings caused by working conditions and structural parameters were investigated. The results show that: small inner ring osculation is useful to reduce the friction torque. Increasing outer ring osculation results in reduction of the friction torque. Too large or too small pocket curvature radius is not conducive to reducing the friction torque. There is a reasonable pocket curvature radius to get the lowest friction torque. The effect of cage pocket clearance on the bearing friction torque is small. A proper bigger cage guiding clearance is beneficial to reducing the friction torque. Properly increasing the radial clearance of double-row spherical roller bearings is useful to reduce the friction torque.