New developments in variable radius gears using constant pressure angle teeth

The purpose of this work is the presentation of a new methodology which greatly increases the contact ratio between the teeth of non-circular gears, using a pressure angle constant for any given tooth, but variable from one to the next. At first an algorithm is proposed to obtain the kinematic synthesis of a pair of variable radius gears, generating a prescribed law of motion. Then, the concept of constant pressure angle non-circular helical gears is introduced and a method to generate a CAD representation proposed. Such gears insure a more progressive meshing, with a softer and less noisy working. In addition, a greater load capacity and duration are obtained.