A ring rolling device includes a drive roller and a rotatable revolving drum, in which five mandrels are rotatably mounted. Ring blanks can be mounted around the mandrels. By rotating the revolver drum, the mandrels move towards and away from the drive roller. The revolver drum is arranged in relation to the drive roller in such a way, that by rotating the revolver drum a decreasing roll gap is formed between a mandrel approaching the drive roller and the drive roller, in which roll gap a ring blank mounted around the mandrel is rolled during the rotating of the revolver drum. The revolver drum has four rotatably mounted support rollers, said support rollers supporting the mandrel in the direction of the rotational axis of the revolving drum, such that, during the rolling process, the mandrel is located between the support rollers and the press element.

The invention relates to a method for modelling the behaviour of a circular rolling mill (1) intended for rolling a cylindrical component on the basis of a setpoint, the circular rolling mill comprising at least one tapered roller (3) configured to effect a translational movement in a first direction (Y), and a mandrel (2), configured to effect a translational movement in a second direction (X), the setpoint comprising a setpoint for the rate of increase of an outside diameter of said cylindrical component as a function of said external diameter, and a setpoint for the height of the cylindrical component in the first direction as a function of a thickness of the cylindrical component in the second direction.

An interaxle differential unit and an axle assembly comprising an interaxle differential unit. The interaxle differential unit comprises an annular case and an interaxle differential unit gear nest. The annular case comprises first and second enlarged lips extending from first and second end surfaces, respectively. The interaxle differential unit gear nest is disposed in the annular case.

A method for producing a ring-rolled material of an FeNi based superalloy, which has a high circularity, can inhibit AGG, and can inhibit grain growth. A method for producing a ring-rolled material of an FeNi based superalloy having a composition of an Alloy 718 comprises: a finishing ring rolling step of heating a ring-shaped material for ring rolling having the composition, in a temperature range of 900 C. to 980 C., and performing finishing ring rolling; and a circularity correcting step of correcting an ellipticalness of the ring-rolled material that has been rolled in the finishing ring rolling step, while expanding a diameter of the ring-rolled material by using a ring expander including a pipe-expanding cone and a pipe-expanding die, wherein the ring-rolled material that has been rolled in the finishing ring rolling step is subjected to circularity correction without being reheated or after having been heated to up to 960 C.

A method for producing a ring-rolled material of an FeNi based superalloy, which has a high circularity, can inhibit AGG, and can inhibit grain growth. A method for producing a ring-rolled material of an FeNi based superalloy having a composition of an Alloy 718 comprises: a finishing ring rolling step of heating a ring-shaped material for ring rolling having the composition, in a temperature range of 900 C. to 980 C., and performing finishing ring rolling; and a circularity correcting step of correcting an ellipticalness of the ring-rolled material that has been rolled in the finishing ring rolling step, while expanding a diameter of the ring-rolled material by using a ring expander including a pipe-expanding cone and a pipe-expanding die, wherein the ring-rolled material that has been rolled in the finishing ring rolling step is subjected to circularity correction without being reheated or after having been heated to up to 960 C.