Abstract: A transmission gear has a tooth surface formed of a free-form surface instead of an involute surface and a root area formed of a free-form surface instead of a trochoid surface. With such a transmission gear, the fatigue strength against contact pressure can be increased by reducing the Hertzian stress in the area around the meshing point of the tooth surface. The tooth surface is formed of a free-form surface in which the smallest radius of curvature in an area around a mating pitch point is maximized, and the fatigue strength against bending can be increased by reducing the bending stress at a tooth root portion of the bottom land. In addition, the gear noise can be reduced. The bottom land is formed of a free-form surface in which the smallest radius of curvature in an area around a tooth root is maximized.

Abstract: A transmission gear has a tooth surface formed of a free-form surface instead of an involute surface and a root area formed of a free-form surface instead of a trochoid surface. With such a transmission gear, the fatigue strength against contact pressure can be increased by reducing the Hertzian stress in the area around the meshing point of the tooth surface. The tooth surface is formed of a free-form surface in which the smallest radius of curvature in an area around a mating pitch point is maximized, and the fatigue strength against bending can be increased by reducing the bending stress at a tooth root portion of the bottom land. In addition, the gear noise can be reduced. The bottom land is formed of a free-form surface in which the smallest radius of curvature in an area around a tooth root is maximized.

Abstract: A helical gear having helical tooth portions of the helical gear being worked by a punch and a die having a land of a smaller distance between opposed working surfaces formed to be inclined than that of other portion, formed on predetermined portions in tooth directions of respective opposed working surfaces thereon, in which worked surfaces on both side of the helical tooth portions on the helical gear as a work are ironed by the land in response to the helical tooth portions passing through the land when the work is forged by the punch.

Abstract: A method for manufacturing a gear and a gear for a transmission, in which an outer peripheral gear part formed on an outer peripheral wall surface of a main body of a gear, an annularly-shaped concave portion annularly formed at a radial inner part on at least one axial end surface of the main body of the gear within the outer peripheral gear part thereof, a dog gear part formed on an outside peripheral wall surface at a central part formed on the annularly-shaped concave portion, and a taper part comprising an inner corn for being synchro formed on an inside peripheral wall surface formed on the annularly-shaped concave portion, are formed integrally by forging.

Abstract: A speed change gear with dog clutch pawls projected on a side surface of a gear body having a speed change gear part on an outer peripheral surface thereof, and a method and a device of manufacturing the same, in which the dog clutch pawls are provided with back tapers on at least engaging surface thereof, and the dog clutch pawls with back tapers and the change gear part are integrally molded by forging.

Abstract: A gear having window holes, and method and apparatus for mafufacturing the same in which by depressing partially one end surface of a primary formed article, a plurality of concaves for the window holes is formed at the one end surface in an axial direction of the primary formed articles, a plurality of projections are extruded from the other end surface thereof and tooth forms preformed at an outer peripheral wall of the primary formed article is thrown out in radial direction thereof, and the gear is formed by cutting the plurality of projections extruded from the other end surface thereof.

Abstract: A gear, a method and a device having a transmission gear part and a hub synchro having a spline teeth formed on an outer peripheral surface thereof and plurality of key holes formed in the opposite side of the transmission gear part, in which the hub synchro is coaxially provided with said transmission gear part, the diameter of the hub synchro is smaller than that of the transmission gear part, and the spline teeth and the plurality of key holes on the hub synchro are formed by forging.

Abstract: A helical gear having helical tooth portions of the helical gear being worked by a punch and a die having a land of a smaller distance between opposed working surfaces formed to be inclined than that of other portion, formed on predetermined portions in tooth directions of respective opposed working surfaces thereon, in which worked surfaces on both side of the helical tooth portions on the helical gear as a work are ironed by the land in response to the helical tooth portions passing through the land when the work is forged by the punch.

Abstract: A method for manufacturing a gear, wherein the gear is formed on a forging process by a die having an inner peripheral surface. A plurality of top surfaces corresponding to a bottom surface of the gear and both projected side surfaces corresponding to tooth surfaces of the gear and sandwiching the top surface connect smoothly to each other. The tooth surfaces and the bottom surface of the formed gear connect to each other smoothly. The forging process is carried out as a hot forging process in which the gear is formed by a hot forging die, or the forging process is carried out as a cold forging process in which the gear is formed by a cold forging die.

Abstract: An idler gear having a part worked by cutting is formed such that a chamfer part is formed at least on a portion between a tooth shape and chamfers are formed on the tooth shape by a forging process on an outer peripheral surface and an end part thereof in an axial direction by cutting.

Abstract: A gear in which forged chamfered portions are formed on the respective ridge line portions at intersections between tooth bottom lands, tooth flanks, and a tooth tip land of the gear and end faces in the axial direction of the gear, and which does not need machining such as cutting to remove burrs caused by hobbing in the conventional techniques.

Abstract: In a gear product, a plurality of tooth having a crowning formed in a pattern unified to one pattern selected from fourteen patterns comprising four patterns in which a crowning is formed at one of an upper end part A or lower end part B of an upper inclined surface 91, an upper end part C or a lower end part D of a lower inclined surface 92, six patterns in which crownings are formed at two parts thereof and four patterns in which crownings are formed with three parts thereof, are formed at an equal pitch on an outer peripheral surface of a gear part. In a helical gear 9, a combination pattern of an upper part A of an upper side tooth surface 91 and a lower part D of a lower tooth surface 92 or a pair of an upper part C of the lower tooth surface 92 and a lower part D of the upper tooth surface 92 is formed by forging device.

Abstract: A speed change gear with dog clutch pawls projected on a side surface of a gear body having a speed change gear part on an outer peripheral surface thereof, and a method and a device of manufacturing the same, in which the dog clutch pawls are provided with back tapers on at least engaging surface thereof, and the dog clutch pawls with back tapers and the change gear part are integrally molded by forging.

Abstract: A method for manufacturing a gear, wherein the gear is formed on a forging process by a die having an inner peripheral surface, on which a plurality of top surface corresponding to a bottom surface of the gear and both projected side surfaces corresponding to tooth surfaces thereof and sandwiching the top surface connect smoothly each other, in which the tooth surfaces and the bottom surface of the formed gear connect to each other smoothly, wherein the forging process is carried out on hot forging process in which the gear is formed by a hot forging die having an inner peripheral surface including a plurality of the top surface corresponding to a bottom surface of the gear and both projected side surfaces corresponding to the tooth surfaces thereof and sandwiching the top surface, and wherein the forging process is carried out on cold forging process in which the gear is formed by a cold forging die having an inner peripheral surface including a plurality of a top surface corresponding to the bottom surface

Abstract: A clutch gear having a boss part with a spline which is formed on an outer peripheral surface of the boss part formed on an axial end surface of the clutch gear having jaw clutch teeth formed on an outer peripheral surface thereof, in which the boss part, with the spline formed on outer peripheral surface thereof, is formed integrally and coaxially with the clutch gear having the jaw clutch teeth formed on the outer peripheral surface thereof by forging, the diameter of the boss part is shorter than that of the clutch gear, and an end part of an effective portion of the spline comes to at least an end surface of the clutch gear.

Abstract: A chamfer processing method for forming a chamfer part in a producing method for molding a product which has a cut-finished surface by cutting and penetrated hole or concave portion opening to said cut-finished surface, wherein chamfer processing step for chamfer processing previously the chamfer part by press molding at a corner part between the cut-finished surface and the penetrated hole or concave portion, and cutting step for cut-finishing the cut-finished surface in order to remain the chamfer part on the corner part between the cut-finished surface and the penetrated hole or concave portion.

Abstract: A transmission gear with a dog clutch gear in which the dog clutch gear has clutch teeth formed on an outer circumferential surface of a ring part and tapered inversely so that the tooth thickness of each tooth decreases gradually from a chamfer portion at a tip end toward a base end portion thereof, and the dog clutch gear is integrally fitted onto a boss portion of the transmission gear which portion is coaxially and integrally formed on a side surface of the transmission gear, characterized in that a flange is provided on the ring part to be located on the side corresponding to the base end portion of the clutch teeth, and plurality of surfaces between the ring part and the transmission gear is performed by welding.

Abstract: A method for manufacturing a gear and a gear for a transmission, in which an outer peripheral gear part formed on an outer peripheral wall surface of a main body of a gear, an annularly-shaped concave portion annularly formed at a radial inner part on at least one axial end surface of the main body of the gear within the outer peripheral gear part thereof, a dog gear part formed on an outside peripheral wall surface at a central part formed on the annularly-shaped concave portion, and a taper part comprising an inner corn for synchro formed on an inside peripheral wall surface formed on the annularly-shaped concave portion, are formed integrally by forging.

Abstract: A gear having window holes, and method and apparatus for mafufacturing the same in which by depressing partially one end surface of a primary formed article, a plurality of concaves for the window holes is formed at the one end surface in an axial direction of the primary formed articles, a plurality of projections are extruded from the other end surface thereof and tooth forms preformed at an outer peripheral wall of the primary formed article is thrown out in radial direction thereof, and the gear is formed by cutting the plurality of projections extruded from the other end surface thereof.

Abstract: Idler gear as an example of gears having a part worked by cutting, and method and apparatus for manufacturing the same in which the chamfer part is formed at least in a portion between a tooth form with chamfers formed by forging process on an outer peripheral surface and the end part thereof in the axial direction by cutting.