Spindle apparatus for use at a machine tool, in particular a lathe, and machine tool with such spindle apparatus

A spindle apparatus for use with a machine tool, comprising:

• a spindle assembly including a workpiece spindle being configured to receive an elongated workpiece and a spindle motor for driving a spindle rotation of the workpiece spindle about a spindle axis of the workpiece spindle;
• and
• a rotary guide-bush assembly being axially arranged with the workpiece spindle with respect to the spindle axis, the rotary guide-bush assembly including a rotary guide-bush configured to receive the elongated workpiece and being supported at the rotary guide-bush assembly to rotate with the elongated workpiece received in the workpiece spindle about the spindle axis while enabling a movement of the elongated workpiece in the direction of the spindle axis;
• wherein
• the spindle assembly and the rotary guide-bush assembly are configured to connect to each other by a torque transferring connection arranged between the spindle assembly and the rotary guide-bush assembly along the spindle axis so as to transfer driving torque during acceleration or deceleration of the spindle rotation driven by the spindle motor to the rotary guide-bush of the rotary guide-bush assembly,
• the torque transferring connection comprises an extensible joint structure, the extensible joint structure including a telescopic coupling tube mechanism having a plurality of tube elements, the telescopic coupling tube mechanism being arranged axially with respect to the spindle axis, and
• a plurality of through holes are formed in a tube wall of an outer tube element of the telescopic coupling tube mechanism having a largest diameter among the tube elements, so that the outer tube element is configured to enable outflow of cooling and/or lubricating liquid from the inside of the telescopic coupling tube mechanism to its outside.