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Helical Gears in Power Transmission System(2014-03-14)

A Industrial Gearbox  transmits the engine power to the driving wheels with the help of different Gearing Systems. Different Gear combinations are used  to give the smooth running, the lower fuel consumption, and the optimum driving comfort. Generally, passenger car transmissions are
provided with 4-5 forward speeds and one reverse speed. In front wheel models, Hypoid Gears have been replaced by Helical Gears. Involute splines, both  external  and  internal,  are  also widely used on various Gear shafts and hubs for slide meshings in transmission system. Bevel Gear and Pinion are still used in differential of automobiles. However, parallel axes Spur Gears and Helical Gears are the Main Gears in automotive transmission.  Manufacturing of Gears presents a demanding challenge for metallurgists in heat treatment, for supervisors in machining and Gear Cutting, and for quality engineers in keeping the quality to the required standards.
Gear Manufacturing process  dynamics are undergoing a major breakthrough in last two decades. Solutions being sought are not corrective but preventative. Normally, either soft Gear Process dynamic or Hard Gear process dynamic is being aimed. Objective is to cut the number of operations or machines through which a work Gear needs to pass to attain the final specifications of dimensions and tooth form quality. 
In soft Gear Process dynamic, the Gear Teeth are generated by Gear  Hobbing or shaping depending on the component design constraints. Soft finishing of Gear Teeth is carried out by Gear Shaving, rolling or grinding to attain the Gear Quality Grade. Even after the heat treatment deterioration, the quality specification remains  well within the desired final specification to meet product final performance requirements such as noise, etc. 
In Hard Gear process dynamic, hobbed and/or shaped, or warm forged/rolled Gears after heat treatment undergo final finishing operation, such as hard finishing,  honing, or grinding.
Overall economy becomes the deciding factor for selection of  the process dynamic.