NC MACHINE TOOL HAVING DIFFERENTIAL MECHANISM TYPE BALL SCREW

PURPOSE:To revolve a shaft without generating feed by correcting the input information supplied from a feeding shaft information input means which inputs the aimed position information to a feeding shaft driving a means, according to the input information supplied from a main spindle information input means. CONSTITUTION:When a shaft 18 is to be turned, a port switch 47 is turned ON by the signal supplied from a port 26, and the number of revolution is inputted from a port 20. The number of revolution is coordinate-converted by a coordinate converter 21, and pulse-analyzed by a distributor 22, and inputted into an adder 23. The signal is supplied, and a main spindle motor 12 revolves, and the shaft 18 revolves at an aimed revolution speed. At the same time, the output supplied from the distributor 22 is multiplied by the resolving power ratio in a converter 27, and inputted into an adder 46, and supplied into a feeding shaft motor 8 through a position controller 36, speed controller 37, electric current controller 38, and a PWM 39. A ball screw nut 3 is revolved through a feeding shaft pulley 9b, feeding shaft timing belt 10, and a feeding shaft pulley 9a by the revolution of the feeding shaft motor 8, and the shaft 18 is kept in standstill by the action of the screw 18a.