Abstract: Bevel gears having a carbon content of at least about 0.4% by weight, preferably 0.5% by weight are manufactured by a process which includes forging a steel blank having a carbon content of at least 0.4% by weight until a bevel gear precursor having essentially the tooth configuration and dimensions of the desired product gear is obtained, and hardening the teeth of the gear precursor by induction heating without machining of the teeth. The initial forging is precise enough so that no further machining of the teeth is required. This requires forging to a tolerance specified in AGMA class 6. The gear is then induction hardened, first by preheating at a lower frequency, say 10 KHz, then induction heating at a higher frequency, say 50 KHz, in order to obtain a desired hardness profile. The desired hardness profile includes the surface hardness of at least 50, preferably 60, on the Rockwell C scale and a core hardness not over Rockwell C 45, preferably from Rockwell 25 to Rockwell 40.

Abstract: A method and apparatus for machining a workpiece from a hardened unmachined part includes the use of non-rotating centers in a turning machine, on which the workpiece is mounted. The shape of the dead centers permits less force to be used in support of the workpiece for reducing friction between the rotating workpiece and non-rotating centers, while exerting a maximum amount of radial holding force to reduce runout in the machining operation. Lubrication can be supplied through the dead centers to further reduce friction and/or an anti-friction coating may be applied to the contacting surface of the centers for this purpose. Machining of the hardened part may be controlled by CNC equipment.

Abstract: A method for machining a part with gear teeth onto an unmachined part to form drive pinion gears is disclosed. A center bore is formed at one end of the part and receives a tool center to mount the part for machining. The center bore includes a plurality of lobes which are in point contact with the lathe center, allowing adjustment between the unmachined part and the lathe center. Drive apertures are formed radially outwardly of this center bore to receive drive pins from the machine tool. Most preferably the drive apertures are slots which provide clearance, facilitating the alignment of the drive pins in the drive apertures.