Abstract
This study is related to Analysis and Experiment of WN helical Rack and Pinion .Tooth contact Analysis and calculation of Hertzian stress was made. By these results, new type WN Rack & Pinion is proposed. Radius of rack is larger than that of conventional design. The authors decided the best radius of concave radius of rack, from both views of sensibility of tooth contact and Hertzian stress in the case of changing the tooth contact mark caused by the misalignment.