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 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 and rotatably about a rotation axis;
• a form roller support retained on the tool holder, the form roller support being moveable in a direction perpendicular to the rotation axis of the tool holder;
• a form roller rotatably supported on the form roller support so as to be rotatable about a rotation axis that is parallel to the rotation axis of the tool holder, the form roller comprising projections on an outer circumferential surface thereof which are configured to form recesses on the circumferential surface that defines the cylindrical bore in the workpiece;
• a control assembly configured to control the form roller support such that the form roller is allowed to be in press contact with the circumferential surface that defines the cylindrical bore in the workpiece at a press contact load of a predetermined value on the basis of a centrifugal force which is exerted on the form roller sue sort and the form roller during rotation of the tool holder;
• and
• at least one of a first load generating member that generates a load which is applied to the form roller support in a direction of advance of the form roller with respect to the circumferential surface that defines the cylindrical bore, and a second load generating member that generates a load which is applied to the form roller support in a direction of retreat of the form roller with respect to the circumferential surface that defines the cylindrical bore,
• wherein the control assembly comprises a radial movement member moveable in a direction perpendicular to the rotation axis of the tool holder, wherein the form roller support is retained by the radial movement member, and
• wherein the first load generating member is a spring disposed between the radial movement member and the form roller support.

An apparatus for forming 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 and rotatably about a rotation axis;
• a form roller support retained on the tool holder, the form roller support being moveable in a direction perpendicular to the rotation axis of the tool holder;
• a form roller rotatably supported on the form roller support so as to be rotatable about a rotation axis that is parallel to the rotation axis of the tool holder, the form roller comprising projections on an outer circumferential surface thereof which are configured to form recesses on the circumferential surface that defines the cylindrical bore in the workpiece;
• a control assembly configured to control the form roller support such that the form roller is allowed to be in press contact with the circumferential surface that defines the cylindrical bore in the workpiece at a press contact load of a predetermined value on the basis of a centrifugal force which is exerted on the form roller support and the form roller during rotation of the tool holder;
• and
• a load generating member that generates a load which is a lied to the form roller support in a direction of advance of the form roller with respect to the circumferential surface that defines the cylindrical bore,
• wherein the load generating member is a spring.

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 and rotatably about a first rotation axis;
• a form roller support retained on the tool holder, the form roller support being moveable in a direction perpendicular to the first rotation axis;
• a form roller rotatably supported on the form roller support so as to be rotatably about a second rotation axis that is offset from and extends parallel to the first rotation axis, the form roller comprising microscopic projections on an outer circumferential surface thereof which are configured to form the microscopic recesses;
• and
• a control assembly configured to control the relative position of the form roller support to the tool holder such that the form roller is allowed to be maintained in press contact with the circumferential surface at a predetermined press contact load to compensate for a centrifugal force exerted on the form roller during rotation of the tool holder.