Ntn Corporation

Satoshi Sugitatsu

Masashi Kitai

Satoshi Fujimoto

Kohei Higashi

A method of processing a crowned portion of a roller includes disposing first and second feed drums so as to extend parallel to each other, each of the first and second feed drums having an outer periphery formed with respective spirally extending threaded guide surfaces, the first and second feed drums being driven to rotate to transport the roller from a first location towards a second location through between the first and second feed drums, and successively processing the crowned portion of the roller, by means of a through feed processing with the use of a grinding stone. The threaded guide surface of one of the first and second feed drums is formed so that an angle of inclination of an outer peripheral surface of the roller relative to a processing surface of the grinding stone is varied in dependence on a roller passing position of the feed drum.

Processing method

A processing apparatus includes two feed drums, each having an outer periphery formed with a spirally extending threaded guide surface and adapted to be driven to rotate, disposed so as to extend parallel to each other, and the feed drums are used to pass a roller through between the feed drums by the rotation thereof while the roller is caused to rollingly contact the mutually opposed threaded guide surface, and also includes a grinding stone for processing a crowned portion of the roller passing thorough between the feed drums. The threaded guide surface of the feed drums is divided into two axially juxtaposed divided threaded surface areas so that an outer peripheral surface of the roller can be supported at two anteroposterior locations.

Processing apparatus and processing method

A workpiece is fixed by a retracting mechanical chuck mounted on a spindle head of a five-axis control machining center. The apparent outer diameter of the workpiece is increased by a jig. Clamp surfaces of the jaws and a support surface of the jig are formed on the machining center. A cutting tool is mounted on a spindle by an automatic tool exchanger. The workpiece is rotated about an axis to grind an end surface of the workpiece to approximately a predetermined target shape, which is a spherical surface. A grinder is then mounted on the spindle by the automatic tool exchanger, and the grinder is set relative to the workpiece by five-axis control such that the inclination angle, the offset amount, etc. satisfy a predetermined relationship according to the desired grinding. The grinder is then fed in the Z-axis direction to form the spherical surface by grinding.

Method of manufacturing roller

A workpiece feeder is capable of feeding a roller to a roller end face processing machine in a stable posture, a roller end face processing machine, and a roller for a rolling bearing processed by such a roller end face processing machine are provided. The workpiece feeder for roller end face processing includes: a carrier ring having a plurality of recesses arranged in a radially-inner surface thereof at a predetermined pitch along a circumferential direction; a regulating wheel fitted into the carrier ring to form roller fitting cavities between a radially-outer surface of the regulating wheel and the plurality of recesses; a carrier support for supporting the carrier ring on a radially-outer side with respect to the plurality of recesses; and rotational force applying means for applying a rotational force to the carrier ring on the radially-outer side with respect to the plurality of recesses.

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Iwata, Japan

Satoshi Sugitatsu