Traction drives offer certain advantages over gear drives. In particular, they generally run more quietly than geared units and provide an opportunity for higher speed and higher efficiency by eliminating sliding motion between contacting elements. Generating adequate normal load at the frictional contact is essential for traction drives. The best way to generate the normal force is the slef-adaptively loading to prevent the rollers under a continuous and high-stress load. In this paper, a novel design of planetary traction-drive device was developed. It is a combination of a planetary cylindrical roller configuration and a logarithmic spiral profile connection. In this device, the sun roller is hollow, and connected to the input shaft by a logarithmic spiral profile. So as the input shaft rotates relative to the sun roller according a certain direction, a wedging action takes place between the input shaft and the sun roller. This makes the sun roller generate a certain amount of elastic deformation, so an appreciable amount of contact load is generated between the contacting elements. The greater the input torque is, the stronger the strength of the wedging action, and the greater the contact load, and vice versa. So this device is self-actuating and self-adaptive. This design offers an alternative way to solve the problem of self-adaptively loading of the planetary cylindrical roller traction drive.