Robot hand, robot and robot system capable of gripping workpiece, and method of rotating and inserting workpiece into hole

A robot system configured to rotate and insert a circular workpiece into a circular hole, the robot system comprising:

• a robot including a robot hand having:
• a first hand section;
• a second hand section including a workpiece gripping section configured to grip a workpiece;
• an elastic member configured to connect the first hand section and the second hand section to each other in an elastically displaceable manner;
• and
• a movement restricting mechanism configured to:
• restrict a rotation movement of an elastic displacement of the second hand section with respect to the first hand section, by mechanically coupling the first hand section to the second hand section, and
• allow a rotation movement and a translation movement of an elastic displacement of the second hand section with respect to the first hand section, by mechanically decoupling the first hand section from the second hand section;
• and
• a controller configured to control the robot so as to rotate the first hand section about an axis of the rotation movement of the second hand section, and along with which, insert the workpiece gripped by the workpiece gripping section into the hole, when the movement restricting mechanism restricts the rotation movement.

A method of gripping a circular workpiece by a robot hand and rotating the workpiece to insert into a circular hole, the robot hand including a first hand section, a second hand section including a workpiece gripping section configured to grip a workpiece, an elastic member configured to connect the first hand section and the second hand section to each other in an elastically displaceable manner, and a movement restricting mechanism configured to restrict a rotation movement of an elastic displacement of the second hand section with respect to the first hand section, by mechanically coupling the first hand section to the second hand section, and allow a rotation movement and a translation movement of an elastic displacement of the second hand section with respect to the first hand section, by mechanically decoupling the first hand section from the second hand section, the method comprising:

• operating the movement restricting mechanism to allow the rotation movement of the second hand section by mechanically decoupling the first hand section from the second hand section;
• when the movement restricting mechanism mechanically decouples the first hand section from the second hand section and allows the rotation movement of the second hand section, gripping the workpiece by the workpiece gripping section;
• operating the movement restricting mechanism to restrict the rotation movement of the second hand section by mechanically coupling the first hand section to the second hand section;
• and
• when the movement restricting mechanism mechanically couples the first hand section to the second hand section:
• moving the robot hand and arranging the workpiece with respect to the hole such that an axis of the workpiece gripped by the workpiece gripping section coincides with an axis of the hole, and
• rotating the first hand section about an axis of the rotation movement, and along with which, inserting the workpiece gripped by the workpiece gripping section into the hole.