Abstract: A method for manufacturing a gear includes rotating a workpiece around a first axis, and rotating a plurality of cutting blades arranged annularly around a second axis skew to the first axis around the second axis. The method further includes, while causing the workpiece and the cutting blades to perform relative movement in a direction parallel to the first axis at a speed synchronized with a rotational speed of the workpiece, forming a helical tooth groove in an outer peripheral surface of the workpiece by the cutting blades. In a cross section perpendicular to the first axis, a diameter of a rolling circle in which an outline of the cutting blades and a target online of the gear make rolling contact with each other is larger than a diameter of a tooth depth center circle.

Abstract: An internal gear includes plural teeth each including an addendum area, a dedendum area, and an intermediate area including a protrusion and a recessed portion. The intermediate area includes a first border position provided at a position between the protrusion and the recessed portion, a second border position provided at a position between the intermediate area and the dedendum area, a third border position provided at a position between the intermediate area and the addendum area, a first average radius provided from the first border position to the second border position, and a second average radius provided from the first border position to the third border position. The first average radius is smaller than the second average radius. The addendum area includes a first curvature radius provided at a first center position in a tooth thickness direction, the first curvature radius being set at a maximum.

Abstract: A form rolling apparatus for applying in-feed form rolling to a rod-shaped material includes a support portion configured to support the rod-shaped material to be axially rotatable, a round die formed with die teeth on an outer periphery thereof, the die teeth configured to be positioned facing an outer periphery surface of the rod-shaped material, and a moving device moving the round die so that a distance of axes of the round die and the rod-shaped material changes. The die teeth includes forming die teeth for generating gear teeth on the outer periphery surface of the rod-shaped material and finishing die teeth enhancing a tooth surface precision of the generated gear teeth by engaging with the generated gear tooth and rotating. The finishing die teeth are formed in a configuration each having an addendum that does not come to contact a bottom land of the generated gear teeth.

Abstract: A valve opening and closing timing control apparatus includes a phase adjustment mechanism of a gear type specifying a relative rotation phase between a driving-side rotation member and a driven-side rotation member by an electric actuator, the phase adjustment mechanism causing a revolution of a position of an eccentric axis about a rotation axis by the electric actuator so that an input gear connected to the driven-side rotation member via an Oldham coupling rotates relative to an output gear fixed to the driven-side rotation member, a groove portion in a linear form and a protruding portion in a rectangular form in the Oldham coupling slidably engaging with each other between the driving-side rotation member and an Oldham ring, a groove portion in a linear form and a protruding portion in a rectangular form in the Oldham coupling slidably engaging with each other between the Oldham ring and the input gear.

Abstract: The inventive device includes a work supporting portion for supporting a work rotatably about a first axis, a cutter supporting portion for supporting a cutter rotatably about a second axis different from the first axis and a moving portion for moving the cutter along a reference line extending through the first axis. The second axis is slanted relative to a reference plane oriented perpendicular to the first axis and a blade edge of the cutter is caused to come into contact with the work at an offset position offset from the reference line. The work and the cutter are driven in synchronism and the cutter is moved along the reference line.

Abstract: An internal gear includes plural teeth each including an addendum area, a dedendum area, and an intermediate area including a protrusion and a recessed portion. The intermediate area includes a first border position provided at a position between the protrusion and the recessed portion, a second border position provided at a position between the intermediate area and the dedendum area, a third border position provided at a position between the intermediate area and the addendum area, a first average radius provided from the first border position to the second border position, and a second average radius provided from the first border position to the third border position. The first average radius is smaller than the second average radius. The addendum area includes a first curvature radius provided at a first center position in a tooth thickness direction, the first curvature radius being set at a maximum.

Abstract: A thread rolling method for a gear using cylindrical dies in which no slippage occurs. The method includes placing a work having a cylindrical outer surface to be supported to a support to be freely rotatable about a rotation axis of the cylindrical outer surface; placing a pair of the cylindrical dies each rotatable about an axis parallel to the rotation axis to face each other across the work; thrusting the pair of cylindrical dies against the work; and determining an outer diameter of the work, when rotary movement of the cylindrical dies and the work rotated together is shifted from friction gear movement to gear movement, in which a dimension obtained by dividing an outer circumferential dimension of a dedendum circle of the tooth grooves by the number of teeth to be formed is equal to an addendum circular pitch of each of the cylindrical dies.

Abstract: A gear machining apparatus includes a skiving mechanism positioning a work to be machined and a pinion type cutter on axes skewing from each other, the skiving mechanism rotating the work at a predetermined position and feeding the cutter while rotating in a direction of a tooth trace of a gear to be formed at the work synchronously to the rotation of the work for producing the gear from the work. The cutter includes a tooth surface which is formed with an involute region having an involute curve in an area including a pitch circle in a tooth depth direction, an addendum region continuously formed from the involute region to an addendum, and a dedendum region continuously formed from the involute region to a dedendum the addendum region and the dedendum region being shaped in a configuration different from the involute region.

Abstract: A form rolling apparatus for applying in-feed form rolling to a rod-shaped material includes a support portion configured to support the rod-shaped material to be axially rotatable, a round die formed with die teeth on an outer periphery thereof, the die teeth configured to be positioned facing an outer periphery surface of the rod-shaped material, and a moving device moving the round die so that a distance of axes of the round die and the rod-shaped material changes. The die teeth includes forming die teeth for generating gear teeth on the outer periphery surface of the rod-shaped material and finishing die teeth enhancing a tooth surface precision of the generated gear teeth by engaging with the generated gear tooth and rotating. The finishing die teeth are formed in a configuration each having an addendum that does not come to contact a bottom land of the generated gear teeth.

Abstract: A method of grinding a cutter for skive-machining a work and a device for grinding the skive-machining cutter which method and device allow formation of a better gear with a cutting operation. The target of grinding is a skive-machining cutter in which a plurality of helical groove portions are formed. A first grinding step is effected for grinding one of a pair of blade lateral faces facing the groove portion. A second grinding step is effected for grinding the other of the pair of blade lateral faces. Then, a third grinding step is effected for forming a blade tip face to be continuous with the blade lateral face formed in the first grinding step and the blade lateral face formed in the second grinding step.

Abstract: The inventive device includes a work supporting portion for supporting a work rotatably about a first axis, a cutter supporting portion for supporting a cutter rotatably about a second axis different from the first axis and a moving portion for moving the cutter along a reference line extending through the first axis. The second axis is slanted relative to a reference plane oriented perpendicular to the first axis and a blade edge of the cutter is caused to come into contact with the work at an offset position offset from the reference line. The work and the cutter are driven in synchronism and the cutter is moved along the reference line.

Abstract: A method for manufacturing a base material for a wave gear which enables the effective suppression of man-hours and manufacturing cost while providing the required strength and elastic deformation characteristics for an external gear of a wave gear. In this manufacturing method, steel having a carbon content of 0.48% or less is subjected to primary molding by being cold worked into the shape of an external gear for a wave gear. The resulting primary molded article is heated to a temperature range in which the main phase of the metallographic structure thereof forms an austenitic structure. The main phase of the metallographic structure is formed into bainite by carrying out quenching to a predetermined temperature higher than the martensitic transformation starting temperature and maintaining the temperature for a predetermined time. The product is then cooled to normal temperature.

Abstract: A form rolling method for an involute gear, which includes a work piece including a cylindrical outer peripheral surface having a predetermined radius, and a round die with an involute tooth profile including an addendum pitch corresponding to a pitch defined by dividing a length of an outer circumference of the work piece by number of teeth of the involute gear. The round die is pressed to the work piece while rotating when form rolling the involuete gear.

Abstract: A thread rolling method for a gear using cylindrical capable of achieving a proper tooth profile by the use of cylindrical dies in which no slippage occur during the processing is provided.

Abstract: A method of manufacturing a gear by a skiving process, the skiving process utilizing a cutter including a rotational axis inclined to a rotational axis of a work to be processed into the gear, the skiving process feeding the cutter in a tooth trace direction of a tooth to be formed at the work in a state where the cutter rotates in synchronization with the work, the method includes a surface hardening process for hardening a work surface of the work before the skiving process is performed.

Abstract: A method for manufacturing a base material for a wave gear which enables the effective suppression of man-hours and manufacturing cost while providing the required strength and elastic deformation characteristics for an external gear of a wave gear. In this manufacturing method, steel having a carbon content of 0.48% or less is subjected to primary molding by being cold worked into the shape of an external gear for a wave gear. The resulting primary molded article is heated to a temperature range in which the main phase of the metallographic structure thereof forms an austenitic structure. The main phase of the metallographic structure is formed into bainite by carrying out quenching to a predetermined temperature higher than the martensitic transformation starting temperature and maintaining the temperature for a predetermined time. The product is then cooled to normal temperature.

Abstract: A method of manufacturing a gear by a skiving process, the skiving process utilizing a cutter including a rotational axis inclined to a rotational axis of a work to be processed into the gear, the skiving process feeding the cutter in a tooth trace direction of a tooth to be formed at the work in a state where the cutter rotates in synchronization with the work, the method includes a surface hardening process for hardening a work surface of the work before the skiving process is performed.

Abstract: A gear machining apparatus includes a skiving mechanism positioning a work to be machined and a pinion type cutter on axes skewing from each other, the skiving mechanism rotating the work at a predetermined position and feeding the cutter while rotating in a direction of a tooth trace of a gear to be formed at the work synchronously to the rotation of the work for producing the gear from the work. The cutter includes a tooth surface which is formed with an involute region having an involute curve in an area including a pitch circle in a tooth depth direction, an addendum region continuously formed from the involute region to an addendum, and a dedendum region continuously formed from the involute region to a dedendum the addendum region and the dedendum region being shaped in a configuration different from the involute region.

Abstract: A gear shape measuring apparatus includes a supporting unit adapted to support a test gear so as to be rotatably driven about a first rotation axis, a gauge gear being rotatable about a second rotation axis while engaging with the test gear, an inter-axis angle setting portion for adjusting and setting a relative inclination angle between the first rotation axis and the second rotation axis, and allowing a distance between the first rotation axis and the second rotation axis to be changed, a biasing member biasing the gauge gear against the test gear, a center-to-center distance measuring portion measuring the distance between the first rotation axis and the second rotation axis, and a measurement data processing portion processing a measurement data.

Abstract: A form rolling method for an involute gear, which includes a work piece including a cylindrical outer peripheral surface having a predetermined radius, and a round die with an involute tooth profile including an addendum pitch corresponding to a pitch defined by dividing a length of an outer circumference of the work piece by number of teeth of the involute gear. The round die is pressed to the work piece while rotating when form rolling the involuete gear.