Apparatus for forming microscopic recesses on a cylindrical bore surface and method of forming the microscopic recesses on the cylindrical bore surface by using the apparatus

An apparatus for forming microscopic recesses on a circumferential surface that defines a cylindrical bore in a workpiece, the apparatus comprising:

• a tool holder disposed coaxially with the cylindrical bore;
• a form roller support disposed on the tool holder so as to be moveable in a direction perpendicular to a central axis of the tool holder;
• a form roller supported on the form roller support so as to be rotatable about a rotation axis that is offset from the central axis of the tool holder in parallel relation thereto, the form roller being operative to form the microscopic recesses on the circumferential surface that defines the cylindrical bore in the workpiece;
• a load applying member that applies a load to the form roller so as to press the form roller against the circumferential surface that defines the cylindrical bore in the workpiece;
• a form roller drive that drives the form roller to rotate about the rotation axis;
• and
• a rotary drive that causes a relative rotation of the workpiece and the tool holder about a central axis of the cylindrical bore in the workpiece.

An apparatus for forming microscopic recesses on a circumferential surface that defines a cylindrical bore in a workpiece, the apparatus comprising:

• a main shaft;
• a tool holder disposed on the main shaft so as to be in axial alignment with the main shaft, the tool holder being rotatable about a rotation axis together with the main shaft;
• a form roller support disposed on the tool holder, the form roller support including a support shaft parallel to the main shaft;
• a form roller supported on the support shaft of the form roller support so as to be rotatable together with the support shaft, the form roller being formed with microscopic projections on an outer peripheral surface thereof;
• a load applying member that applies a load to the form roller support in a radial direction of the form roller to press the microscopic projections of the form roller against the circumferential surface that defines the cylindrical bore in the workpiece under condition that the rotation axis of the tool holder is in alignment with a central axis of the cylindrical bore;
• and
• a rotational resistance varying member that vary rotational resistance of the form roller.

An apparatus for forming microscopic recesses on a circumferential surface that defines a cylindrical bore in a workpiece, the apparatus comprising:

• a form roller having microscopic projections on an outer peripheral surface thereof which are configured to form the microscopic recesses;
• a form roller support that supports the form roller so as to be rotatable about a rotation axis;
• a tool holder that retains the form roller support such that a central axis of the cylindrical bore in the workpiece is parallel to the rotation axis of the form roller;
• a form roller pressing drive that presses the form roller against the circumferential surface that defines the cylindrical bore in the workpiece;
• a rotary drive that causes a relative rotation of the workpiece and the tool holder about the central axis of the cylindrical bore in the workpiece;
• an axial drive that causes a relative axial movement of the workpiece and the tool holder along the central axis of the cylindrical bore in the workpiece;
• and
• a control unit that controls the axial drive to vary a speed of the relative axial movement of the workpiece and the tool holder on the basis of a diameter of the cylindrical bore in the workpiece.

An apparatus for forming microscopic recesses on a circumferential surface that defines a cylindrical bore in a workpiece, the apparatus comprising:

• a form roller having microscopic projections on an outer peripheral surface thereof which are configured to form the microscopic recesses;
• a form roller support that supports the form roller so as to be rotatable about a rotation axis;
• a tool holder that retains the form roller support such that a central axis of the cylindrical bore in the workpiece is parallel to the rotation axis of the form roller;
• a form roller pressing drive that presses the form roller against the circumferential surface that defines the cylindrical bore in the workpiece;
• a rotary drive that causes a relative rotation of the workpiece and the tool holder about the central axis of the cylindrical bore in the workpiece;
• an axial drive that causes a relative axial movement of the workpiece and the tool holder along the central axis of the cylindrical bore in the workpiece;
• and
• a control unit that controls the axial drive to vary a speed of the relative axial movement of the workpiece and the tool holder on the basis of an error of an actual pattern of the microscopic recesses formed on the circumferential surface that defines the cylindrical bore in the workpiece with respect to a reference pattern of the microscopic recesses.