A method for manufacturing a gear which effectively prevent a crack from occurring inside a tooth part when rolling processing is performed on a teeth part of a gear raw material is achieved. A method according to one embodiment for manufacturing a gear by performing rolling processing on a tooth part of a sintered gear raw material. The method includes, when the rolling processing is performed on the tooth part of the gear raw material, pressing the gear raw material toward a center of rotation of the gear raw material by a rolling machine and, when at least the rolling processing is performed on the tooth part of the gear raw material toward a center of a thickness thereof by a pressing machine, pressing a region where an internal density of the tooth part of the gear raw material decreases.

A method for manufacturing a gear which effectively prevent a crack from occurring inside a tooth part when rolling processing is performed on a teeth part of a gear raw material is achieved. A method according to one embodiment for manufacturing a gear by performing rolling processing on a tooth part of a sintered gear raw material. The method includes, when the rolling processing is performed on the tooth part of the gear raw material, pressing the gear raw material toward a center of rotation of the gear raw material by a rolling machine and, when at least the rolling processing is performed on the tooth part of the gear raw material toward a center of a thickness thereof by a pressing machine, pressing a region where an internal density of the tooth part of the gear raw material decreases.

A tooth shape of the first tooth-shaped die part is formed have a constant tooth width from an upper end to a lower end and to correspond to a tooth width of a part in which a desired crowning has been produced. A tooth shape of the second tooth-shaped die part is formed to have a constant tooth width from an upper end to a lower end and to correspond to a tooth width of a central part, which is a part other than the part in which the desired crowning has been produced. A crowning forming method includes the steps of: forming a tooth shape on an outer circumference of the material by the tooth shape of the first tooth-shaped die part; and pressing the central part of the tooth shape of the material against the tooth shape of the inner circumference of the second tooth-shaped die part.

A method wherein a cutting or grinding chamfering tool (25) is guided along the face width of a gear (12, 23, 52) through one tooth slot (8) (e.g. from heel to toe) while it contacts the topland corners (10, 1 1) of the respective concave and convex tooth flanks of adjacent teeth (2, 4). The tool moves to an index position, the gear is indexed to the next tooth slot position and the tool moves through the tooth slot (e.g. from the toe to the heel). The cycle is repeated until all topland corners are chamfered.

A method wherein a cutting or grinding chamfering tool (25) is guided along the face width of a gear (12, 23, 52) through one tooth slot (8) (e.g. from heel to toe) while it contacts the topland corners (10, 1 1) of the respective concave and convex tooth flanks of adjacent teeth (2, 4). The tool moves to an index position, the gear is indexed to the next tooth slot position and the tool moves through the tooth slot (e.g. from the toe to the heel). The cycle is repeated until all topland corners are chamfered.

The invention relates to a method and a machine tool for hard finishing toothed gearing, particularly internally toothed portions (3), in which method a toothed hard finishing tool (W) which rotates about its axis of rotation is brought into rolling machining engagement with the machined toothed gearing in one pass or in a plurality of passes of differing radial infeed depth under an advance motion with a direction component parallel to the axis of rotation (C) of the machined toothed gearing and under a non-null axis crossing angle, and material is removed from the machined toothed gearing with a tooth flank region (4a) of the machine tool gearing with tooth thickness increasing in the tooth trace direction from the end face (5) facing the machined toothed gearing.

A shot treatment apparatus and a shot treatment method applicable to the mass production of a wide range of products. A shot treatment apparatus, comprising: a spinning table which has a first rotary shaft and which holds and rotates a workpiece; an ejection apparatus that ejects a shot media from a nozzle to the workpiece; a cabinet having a treatment chamber formed therein; and a control apparatus comprising a first control unit that controls the ejection apparatus, the nozzle being held so as to be positionable and three-dimensionally swingable with respect to the workpiece.

There is provided a method of forming a ring gear, including providing a tube having an inner surface comprising gear teeth, the tube being a hollow tube formed by extrusion. The method also includes inserting a shaping tool into the tube, the shaping tool having tool teeth to mate with the gear teeth, and extended and retracted configurations. The shaping tool may be inserted into the tube in its retracted configuration. Moreover, the method includes extending the shaping tool into its extended configuration to cause the tool teeth to mate with the gear teeth and to exert a radially outward force on the tube. Furthermore, the method includes fixing a shape of an outer perimeter of the tube, retracting the shaping tool into its retracted configuration to reduce the radially outward force exerted by the shaping tool on the tube, and removing the shaping tool from the tube.

A gear machining support device supports machining when a tooth of a gear is machined on a workpiece by relatively moving the workpiece and a machining tool while synchronizing rotations of the workpiece and the machining tool around respective center axis lines thereof. The gear machining support device includes: a target modification amount storage unit configured to store target modification amounts of at least two of modification elements of a tooth surface shape of the tooth of the gear, the modification elements including crowning, bias, a helix angle, a pressure angle, and a tooth profile roundness; and a correction amount determination unit configured to determine a correction amount of a machining control element during a machining operation such that the at least two of modification elements approximate the respective target modification amounts stored in the target modification amount storage unit.

A method for detecting a phase on a gear includes obtaining a first determination result indicating whether the gear has been detected at a first detection position. A second determination result indicating whether the gear has been detected at a second detection position is obtained. A third angle between the first and second angles is obtained. A third determination result indicating whether the gear has been detected at a third detection position is obtained. The first angle is replaced with the third angle when the third and first determination results are same, or the second angle is replaced with the third angle when the third and first determination results are different. The phase on the gear is detected based on an angle that is between the first angle and the second angle.