To provide a method of manufacturing a shaft for a steering device, the shaft including a spline shaft part to be coupled with an input shaft, a stopper part to be coupled with an output shaft, and an intermediate shaft part that couples the spline shaft part with the stopper part. The method includes: a step of forming a hole part recessed in an axial direction from one end of a pillar-shaped material by forging; and a step of pressing the material in which the hole part has been formed into a die to perform drawing in a radial direction on a portion of the material at which the spline shaft part and the intermediate shaft part are formed, and prolonging a length along the axial direction of the hole part at the same time by forging.

To provide a method of manufacturing a shaft for a steering device, the shaft including a spline shaft part to be coupled with an input shaft, a stopper part to be coupled with an output shaft, and an intermediate shaft part that couples the spline shaft part with the stopper part. The method includes: a step of forming a hole part recessed in an axial direction from one end of a pillar-shaped material by forging; and a step of pressing the material in which the hole part has been formed into a die to perform drawing in a radial direction on a portion of the material at which the spline shaft part and the intermediate shaft part are formed, and prolonging a length along the axial direction of the hole part at the same time by forging.

A sprocket wheel, which is a machine component configured to slide relative to a bushing while being in contact with the bushing in an outer peripheral surface, includes a base made of a first metal, and an overlay that covers the base so as to constitute the outer peripheral surface. The surface of the overlay constituting the outer peripheral surface has been smoothed. Such a smoothed surface of the overlay makes the sprocket wheel less damaging to the bushing.

The present invention belongs to the field of mechanical engineering and materials, more specifically in the metallurgy segments, for application in the sugar industry. The invention relates to the hot forging process of mill shafts and heat-treated auxiliary equipment in CrNiMo and low carbon alloy. The shafts and auxiliary equipment manufactured according to this invention have a long service life, thus reducing downtime for maintenance and increasing reliability, since it eliminates the problems associated with cracks and instantaneous fractures. As a consequence, there is a reduction in the risks of accidents and production losses associated with stoppages.

The present invention belongs to the field of mechanical engineering and materials, more specifically in the metallurgy segments, for application in the sugar industry. The invention relates to the hot forging process of mill shafts and heat-treated auxiliary equipment in CrNiMo and low carbon alloy. The shafts and auxiliary equipment manufactured according to this invention have a long service life, thus reducing downtime for maintenance and increasing reliability, since it eliminates the problems associated with cracks and instantaneous fractures. As a consequence, there is a reduction in the risks of accidents and production losses associated with stoppages.

Provided are a motor device and a method for manufacturing the same that can accurately and consistently provide a support shaft to a case and enhance the strength for fixing the support shaft to the case. A small-diameter part having a smaller diameter than a large-diameter part is formed through drawing. The large-diameter part and a step part are embedded in a gear case. The small-diameter part is exposed outside the gear case. The dimensional accuracy (dimensional tolerance ±α) of the external diameter of the small-diameter part is enhanced. The small-diameter part can be set, without rattling, in a lower mold for molding the gear case. Consequently, the support shaft can be accurately and consistently provided to the gear case. Because the large-diameter part and the step part are embedded in the gear case, the resistance of the support shaft against pulling from the gear case can be enhanced.

A method for simply producing components suitable for use under high loads and risks of wear and which have a core portion which consists of a metal material and a wear-resistant layer on a peripheral surface of the core portion is disclosed. A core portion blank is provided and consists of the metal material whose dimension in a first spatial direction is greater than the desired finished dimension of the core and whose second dimension is smaller than the desired finished dimension is provided. A material that forms a wear-resistant layer in the component is applied to a peripheral surface of the core portion blank. The composite body is shaped to form the component. The component may then be optionally finished.

A method for simply producing components suitable for use under high loads and risks of wear and which have a core portion which consists of a metal material and a wear-resistant layer on a peripheral surface of the core portion is disclosed. A core portion blank is provided and consists of the metal material whose dimension in a first spatial direction is greater than the desired finished dimension of the core and whose second dimension is smaller than the desired finished dimension is provided. A material that forms a wear-resistant layer in the component is applied to a peripheral surface of the core portion blank. The composite body is shaped to form the component. The component may then be optionally finished.

Provided are a motor device and a method for manufacturing the same that can accurately and consistently provide a support shaft to a case and enhance the strength for fixing the support shaft to the case. A small-diameter part having a smaller diameter than a large-diameter part is formed through drawing. The large-diameter part and a step part are embedded in a gear case. The small-diameter part is exposed outside the gear case. The dimensional accuracy (dimensional tolerance ±α) of the external diameter of the small-diameter part is enhanced. The small-diameter part can be set, without rattling, in a lower mold for molding the gear case. Consequently, the support shaft can be accurately and consistently provided to the gear case. Because the large-diameter part and the step part are embedded in the gear case, the resistance of the support shaft against pulling from the gear case can be enhanced.

A method for manufacturing a steering shaft of a steering device includes: a reduced-diameter section forming process in which a second-phase member is formed from a first-phase member by forming a reduced-diameter section in the first-phase member; and a ball screw groove forming process in which a third-phase member is formed from the second-phase member by forming a ball screw groove in the second-phase member by rolling.