Provided are a hollow drive shaft and a method for manufacturing the same in which a concentrated load to a weak point which may be occurred by differences of sectional thicknesses and outer diameters of the shaft is dispersed so that the strength may be uniform throughout the whole length of the drive shaft. The hollow drive shaft includes: one or more small-diameter portion having a hollow shape; and a large-diameter portion which is disposed in a vicinity of the small-diameter portion and has an outer diameter relatively greater than the small-diameter portion. A sectional thickness of the large-diameter portion is less than a sectional thickness of the small-diameter portion, and a first sectional portion from an outer surface to a point corresponding to 35% to 60% of a sectional thickness of the large-diameter portion is carburized to have a first hardness.

In a method for thickening a plastically deformable hollow body wall of a hollow body, with effective radial support of the unthickened hollow body wall on an outer supporting face of an outer mold and with effective radial support of the hollow body wall on an inner supporting face of an inner supporting body, the hollow body is acted on by a compressive force by two application members at application points by moving the application members towards one another in the axial direction with a compressing movement. The application points on the hollow body are distanced from one another in the axial direction. An expansion space of the outer mold is arranged between the application points. Due to the compressing movement of the application members, material of the hollow body wall between the application points is plasticised in the region of the expansion space of the outer mold, and plasticised material of the hollow body wall flows into the expansion space of the outer mold, thus thickening the hollow body wall.

A drive shaft for motor vehicles comprises shaft portions arranged one after the other in s longitudinal direction of the drive shaft. One shaft portion is a tubular shaft portion having a large cross section and another shaft portion having a cross section that is smaller than the tubular shaft portion having a large cross section. A transition region having a region wall is provided between the tubular shaft portion and the shaft portion having the smaller cross section. If the drive shaft is compressed in the event of a crash, the shaft portion having the smaller cross section is pushed into the tubular shaft portion having the large cross section by an insertion length, thus deforming or breaking the region wall of the transition region.

A method of manufacturing a light rotor shaft for eco-friendly vehicles is provided which includes cutting a pipe material in a specified length to provide a pipe blank and forming the pipe blank to provide a first form having the first segment on a first side. The method further includes, forming a second form having the second segment by inserting and rotating a first side of a mandrel into the first side of the first form and concurrently hammer-forging the second side of the first form to form the second segment. The rotor shaft includes a third segment formed by inserting and rotating the second side of the mandrel into the first side of the second form to form the third segment.

A motor shaft of an electric motor is produced by producing and interconnecting a first module and an additional module of the motor shaft. The first module of the motor shaft and/or the additional module of the motor shaft is or are provided with a module-end connection element by cold forming and/or by warm forming and/or by hot forming a base module. The first module of the motor shaft produced in this way and the additional module of the motor shaft produced in this way are then interconnected by joining the module-end connection elements on both ends. A motor shaft produced according to this method is formed of a correspondingly configured first module and a correspondingly configured additional module.

The present disclosure relates to a steel forging process, in particular a hot steel forging process in horizontal press of a metal tube, preferably a cylindrical steel tube.

A hollow forging process for main shaft of large wind turbine generator, wherein, comprising the following steps as: the first step of cutting off the dead head and the bottom of an ingot; the second step of upsetting and punching a hole; the third step of drawing-out; and the fourth step of local upsetting, drawing-out and shaping-up. In the fourth step, the forged piece is shaped up by local upsetting and drawing-out through a turnplate. The hollow forging process for main shaft created by the invention can save the costs for enterprise to purchase large equipment and makes it possible to forge the main shaft of large wind turbine generator with a free forging oil press with a smaller size.

A method for producing a shaft, in particular a balance shaft, crankshaft and the like, having at least one substantially annular bearing seat and at least one unbalance portion. The method includes the steps: provision of a shaft blank; formation of the at least one unbalance portion and of at least two opposite bearing seat side members by a forming process; and deformation of the at least two opposite bearing seat side members by a shell tool such that the bearing seat side members are bent together, whereby the at least one substantially annular bearing seat is formed.

A method is used to manufacture a drawn tube having a hollow low interior for housing an axle shaft. The method includes the steps of placing a billet into a first die assembly and pressing the billet into the first die to producing a pre-formed billet. The method also includes the steps of moving the pre-formed billet from the first die assembly to a second die assembly and pressing the pre-formed billet into the second die assembly to produce an extruded tube. The method further includes the steps of moving the extruded tube from the second die assembly to a third die assembly and pressing the extruded tube into the third die assembly to further elongate the extruded tube and decrease the thickness of the wall of the extruded tube to of from about 3 to about 18 millimeters to produce the drawn tube having the yield strength of at least 750 MPa.

A drive axle shaft and method for making the same are provided. The drive axle shaft includes an elongate tubular body and a wheel flange. The elongate tubular body has a longitudinal axis and comprises a first end portion and a second end. The second end is configured to be coupled to a side gear in a differential. The wheel flange is disposed at the first end portion and is configured to support a vehicle wheel. The elongate tubular body and the wheel flange are formed as a unitary body without any weld therebetween.