In a ring-rolling machine having a mandrel roll and a related radial roll, the mandrel roll can be handled in operationally reliable and structurally simple manner if an axial bearing of the mandrel roll is opened by way of an opening drive that does not rotate along with the mandrel roll and/or is closed by inserting the mandrel roll into the axial bearing.

In a ring-rolling machine having a mandrel roll and a related radial roll, the mandrel roll can be handled in operationally reliable and structurally simple manner if an axial bearing of the mandrel roll is opened by way of an opening drive that does not rotate along with the mandrel roll and/or is closed by inserting the mandrel roll into the axial bearing.

A ring rolling mill includes: a rotary drive main roll and a mandrel roll, which are for reducing the thickness of and rolling a ring-shaped material from the radial direction; a pair of rotary drive axial rolls for reducing the thickness of and rolling the ring-shaped material from the axial direction; a measuring roll for measuring the diameter of the ring-shaped material during rolling; and a speed control unit for controlling the speed of the axial rolls. The speed control unit is configured to repeat measuring the diameter at predetermined time intervals t and comparing a measurement value L.sub.t of the diameter at time t and a measurement value L.sub.t+t of the diameter at time t+t, and the speed control unit is further configured to maintain the speed of the axial rolls unchanged upon the result of the comparison being L.sub.t+t<L.sub.t.

A ring rolling mill includes: a rotary drive main roll and a mandrel roll, which are for reducing the thickness of and rolling a ring-shaped material from the radial direction; a pair of rotary drive axial rolls for reducing the thickness of and rolling the ring-shaped material from the axial direction; a measuring roll for measuring the diameter of the ring-shaped material during rolling; and a speed control unit for controlling the speed of the axial rolls. The speed control unit is configured to repeat measuring the diameter at predetermined time intervals t and comparing a measurement value L.sub.t of the diameter at time t and a measurement value L.sub.t+t of the diameter at time t+t, and the speed control unit is further configured to maintain the speed of the axial rolls unchanged upon the result of the comparison being L.sub.t+t<L.sub.t.

A method for rolling a ring-shaped rolling product (5) having an open cylindrical cross section in a ring rolling machine (1) with inductive heating of the rolling product (5) during the rolling process uses at least one inductor (12) which is held at a predefined coupling distance relative to the rolling product (5) and is tracked or carried along during the shaping process in accordance with the change in dimensions of the rolling product (5). An alternating magnetic field, preferably with a frequency of between 4 and 10 kHz, is coupled directly into the rolling product (5) using the inductor (12).

A method for rolling a ring-shaped rolling product (5) having an open cylindrical cross section in a ring rolling machine (1) with inductive heating of the rolling product (5) during the rolling process uses at least one inductor (12) which is held at a predefined coupling distance relative to the rolling product (5) and is tracked or carried along during the shaping process in accordance with the change in dimensions of the rolling product (5). An alternating magnetic field, preferably with a frequency of between 4 and 10 kHz, is coupled directly into the rolling product (5) using the inductor (12).

A ring rolling process and corresponding apparatus are disclosed. A ring shaped workpiece is provided, the ring shaped workpiece having a principal axis, an inner radial surface, an outer radial surface, a first axial surface and a second axial surface. The workpiece is subjected to radial pressure between a forming roll 150a acting on the outer radial surface and a mandrel roll 152a, 152b acting on the inner radial surface, at a radial roll bite region. A first axial roll 154a and a second axial roll 156a are provided at the first axial surface and the second axial surface respectively, to subject the workpiece to axial pressure. The first and second axial rolls 154a, 156a are provided at an angular position, measured around the workpiece and with respect to the principal axis, within 10 of said radial roll bite region. Multiple circumferential constraint rolls are provided around the outer radial surface or inner radial surface. In order to control the cross sectional shape of the workpiece, the mandrel roll 152a, 152b and/or the forming roll 150a has a projecting portion for contact with the workpiece, the projecting portion having an axial extent which is smaller than the axial height of the workpiece, the mandrel roll and/or forming roll being axially moveable relative to the workpiece.

A ring rolling process and corresponding apparatus are disclosed. A ring shaped workpiece is provided, the ring shaped workpiece having a principal axis, an inner radial surface, an outer radial surface, a first axial surface and a second axial surface. The workpiece is subjected to radial pressure between a forming roll 150a acting on the outer radial surface and a mandrel roll 152a, 152b acting on the inner radial surface, at a radial roll bite region. A first axial roll 154a and a second axial roll 156a are provided at the first axial surface and the second axial surface respectively, to subject the workpiece to axial pressure. The first and second axial rolls 154a, 156a are provided at an angular position, measured around the workpiece and with respect to the principal axis, within 10 of said radial roll bite region. Multiple circumferential constraint rolls are provided around the outer radial surface or inner radial surface. In order to control the cross sectional shape of the workpiece, the mandrel roll 152a, 152b and/or the forming roll 150a has a projecting portion for contact with the workpiece, the projecting portion having an axial extent which is smaller than the axial height of the workpiece, the mandrel roll and/or forming roll being axially moveable relative to the workpiece.

The invention relates to a method for shaping a workpiece having a drum-type peripheral wall, on the inner face of which an inner profile featuring longitudinal ribs is formed by feeding at least one profiling roll to said inner face. According to the invention, at least one rotatably mounted profiling roll is fed to an inner face of the peripheral wall of the workpiece, and said at least one profiling roll rotates relative to the inner face of the peripheral wall such that the inner profile is formed in the inner face in a non-cutting manner.

Provided is an endless metal ring manufacturing method for manufacturing an endless metal ring by carrying out a barrel polishing step for polishing the endless metal ring by using a barrel of a resin material, a rolling step for rolling the endless metal ring which was cleaned, and a nitriding step for nitriding the endless metal ring which was rolled, wherein after the barrel polishing step and before the rolling step, provided is a resin removing step for removing resin that has adhered to the endless metal ring.