Abstract: The apparatus for grinding rough-cut longitudinally curved gear teeth of a helical bevel gear, comprises two spindles for respectively mounting a tool and a workpiece, and structure for translatably and adjustably arranging at least one spindle of these two spindles. A separate electric motor arranged coaxially with each of the two spindles serves for driving the tool and for driving the workpiece, respectively. The separate electric motors are mutually interconnected by an electric shaft.

Abstract: An apparatus for driving the generating or rolling cradle of a gear-cutting machine, comprising a variable-speed motor for changing the generating or rolling speed. A cam plate is secured to the rolling cradle in order to control the variable-speed motor as a function of the position of the rolling cradle.

Abstract: A gear cutting machine comprising a tool rotating about a first axis, the first axis being rotatable about a second axis at a first cone-shaped shell or cone, the second axis being rotatable about a second cone-shaped shell or cone about a third axis. There is further provided a gear drive possessing two pairs of bevel gears. The cone apex-cone angles of the bevel gears of one pair of bevel gears are of the same magnitude as the cone apex-cone angles of the bevel gears of the other pair of bevel gears, such cone angles are obtuse, and both of the pairs of bevel gears are connected with one another through the agency of a pair of spur gears.