ABSTRACT

Hobs are widely used for machining gears. The automotive industry is the main consumer of hobs and hobbed gears. As an illustrative example, climb hobbing of a spur gear is illustrated in this chapter. Hobbing is usually and justifiably regarded as the accurate method of gear production, and more thought and mechanical skill have been expended on hobbing machines and their correct functioning than on any other type of gear cutting machine. The process lends itself to the production of all types of gear, including those based on cones that constitute a special application, and it is unlikely to be superseded in the foreseeable future, particularly when large externally toothed cylindrical gears of high accuracy are required. Numerous designs of conical tools for machining cylindrical (spur and helical) gears are known from Dr. Radzevich, and others. Numerous methods for relief grinding, as well as of sharpening of conical gear cutting tools, are developed.