Machine Tool Comprising a Rotary Transmission Leadthrough Between the Driven Gear and the Spindle

A machining tool gear mechanism in which torque is transmitted from an output shaft of the machining tool gear mechanism directly to a spindle, the machining tool gear mechanism comprising:

• a rigid bushing (16) coupling the output shaft (3) of the machining tool gear mechanism to the spindle (6), the rigid bushing (16) having internal gears which engage with external gears of the output shaft (3) of the machining tool gear mechanism and external gears of the spindle (6);
• a rotary passage (14) being located within the spindle (6) and having a first sealing disk (17) and a second sealing disk (18), the first sealing disk (17) communicating with the spindle (6) at an end of a passageway that axially extends through the spindle (6), the second sealing disk (18) communicating with a pipe (15) that extends from the output shaft (3) of the machining tool gear mechanism, the first sealing disk (17) and the second sealing disk (18) being biased together by a first spring to enabling one of a coolant, an emulsion, an oil and air to freely flow through the rotary passage (14) between the output shaft (3) of the machining tool gear mechanism and the spindle (6);
• and
• a check valve (23) being located within the rotary passage (14) to one of allow and prevent a free flow of the coolant, the emulsion, the oil and the air, between the output shaft (3) of the machining tool gear mechanism and the spindle (6), depending on a pressure within the rotary passage (14), and the check valve (23) being biased by a second spring to close when the rotary passage (14) is essentially unpressurized.