Workpiece support and machine tool

A workpiece support comprising:

• a rotating shaft having a first axis and a leading end portion, the rotating shaft being configured to support a workpiece at the leading end portion, the workpiece being to be machined by a tool;
• 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 including 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;
• and
• an attachment provided in contact with an inner surface of the through hole, at least a part of the attachment being displaceable in a direction toward the first axis so that a third distance between the first axis and an innermost portion of the attachment provided in the through hole is smaller than a fourth distance between the first axis and an innermost surface of the through hole.

A machine tool comprising:

• a workpiece support;
• a tool holder configured to hold a tool;
• and
• a second drive configured to move the tool holder,
• wherein the workpiece support comprises
• a rotating shaft having a first axis and a leading end portion, the rotating shaft being configured to support a workpiece at the leading end portion, the workpiece being to be machined by the tool;
• 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 including 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;
• and
• an attachment provided in contact with an outer surface of the leading end portion of the rotating shaft, at least a part of the attachment being displaceable in a direction away from the first axis so that a first distance between the first axis and an outermost portion of the attachment provided at the leading end portion of the rotating shaft is larger than a second distance between the first axis and an outermost surface of the leading end portion of the rotating shaft.