Workpiece support, machine tool, and method of using machine tool

A machine tool comprising:

• a tool holder configured to hold a tool which is configured to machine a workpiece;
• a second drive configured to move the tool holder;
• and
• a workpiece support comprising:
• a rotating shaft having a first axis and a leading end portion and being configured to support the workpiece at the leading end portion;
• a second support supporting the rotating shaft rotatably about the first axis and configured to move the rotating shaft along the first axis;
• a first support provided between the tool and the second support along the first axis and having a through hole into which a guide bushing unit is configured to be inserted and into which the leading end portion of the rotating shaft is configured to be inserted, the guide bushing unit being configured to support the workpiece when the guide bushing unit is in the through hole, an ejection opening being provided on an inner circumferential surface of the through hole of the first support;
• and
• an air supplier configured to supply air to the first support via the ejection opening.

A method of using a machine tool, comprising:

• supporting a first workpiece at a leading end portion of a rotating shaft which is supported by a second support of the machine tool rotatably about a first axis;
• inserting a guide bushing unit into a through hole of a first support which is provided between a tool and the second support along the first axis;
• supporting the first workpiece by the guide bushing unit which is in the through hole;
• rotating the rotating shaft about the first axis together with the first workpiece;
• machining the first workpiece via the tool while the first workpiece is rotated about the first axis;
• removing the guide bushing unit from the through hole;
• supporting a second workpiece at the leading end portion of the rotating shaft;
• moving the rotating shaft along the first axis to insert the leading end portion of the rotating shaft into the through hole of the first support;
• rotating the rotating shaft about the first axis together with the second workpiece;
• machining the second workpiece via the tool while the second workpiece is rotated about the first axis;
• and
• ejecting air toward the leading end portion of the rotating shaft via an ejection opening provided on an inner circumferential surface of the through hole of the first support while the second workpiece is machined.