Method of grinding the teeth of bevel gears having longitudinally curved teeth

An apparatus for finish machining tooth flanks of a number of longitudinally curved teeth of a rough machined bevel gear blank for a hypoid bevel gear pair, comprising a ring gear and a pinion gear, by means of a rotary form tool, comprising:

• a machine bed;
• two slides arranged on said machine bed to be translatable toward one another;
• a first spindle having a lengthwise axis and serving for mounting the rough machined bevel gear blank defining a workpiece arranged on one of said two slides;
• a second spindle having a lengthwise axis and serving for mounting the rotary form tool and arranged on the other of said two slides;
• said slides constituting means for translatably adjusting said first spindle and said second spindle;
• a separate electric motor arranged coaxially with respect to each of said two spindles for respectively driving the rotary form tool and the workpiece at a first and a second speed of rotation, respectively;
• means defining an electric shaft;
• said separate electric motors being mutually interconnected by said electric shaft, for synchronizing said first and said second speed of rotation in a predetermined ratio;
• said slides each comprising a rotary table with a housing for journalling a respective one of said two spindles and a therewith associated one of said separate electric motors;
• said rotary tables each having an axis of rotation;
• at least one housing of said housings being mounted on one of said rotary tables to be translatable in relation to said axis of rotation of the associated rotary table;
• said rotary tables each being rotatable such that there can be selectively adjusted the angle between the lengthwise axes of the first and second spindles;
• one of said spindles being arranged such that the lengthwise axis thereof intersects the axis of rotation of the associated rotary table;
• and
• the other of said spindles being arranged such that the lengthwise axis thereof is arranged offset with respect to the axis of rotation of the associated rotary table.