The present invention relates to rope drums for winding and unwinding ropes, having a drum shell, to which end disks are fastened at the end faces, and to rope winches having such rope drums. The invention also relates to a method for producing such a rope drum. According to the invention, the drum shell is seamlessly rolled from an annular workpiece blank by means of a rope groove profile embossed in a non-cutting manner.

A method for manufacturing a ring-rolled product, which manufactures the ring-rolled product from a ring material, includes a step of rolling the ring material, which has an operation of rolling the ring material from both inner and outer circumferential sides thereof between a mandrel roll and a main roll in a state of rotating the ring material toward one side in a circumferential direction thereof, and induction-heating the ring material by induction heating elements. An induction heating element is disposed on only an outer circumferential side of the ring material or is disposed on each of both the inner and outer circumferential sides in a region immediately before the rolling, or an inclined portion is provided in an outer-peripheral edge portion of a coil in the induction heating element.

A method for manufacturing a ring-rolled product, which manufactures the ring-rolled product from a ring material, includes a step of rolling the ring material, which has an operation of rolling the ring material from both inner and outer circumferential sides thereof between a mandrel roll and a main roll in a state of rotating the ring material toward one side in a circumferential direction thereof, and induction-heating the ring material by induction heating elements. An induction heating element is disposed on only an outer circumferential side of the ring material or is disposed on each of both the inner and outer circumferential sides in a region immediately before the rolling, or an inclined portion is provided in an outer-peripheral edge portion of a coil in the induction heating element.

A method for manufacturing a ring-rolled product forms the ring-rolled product from a ring material by using a mandrel roll and a main roll. The mandrel roll and the main roll are configured so as to contact inner and outer circumferential surfaces of the ring material, respectively, and are configured so as to press the ring material in a radial direction thereof in a state in which the ring material is rotated in a circumferential direction thereof. The method includes a step of rolling the ring material that includes an operation of induction-heating the main roll by at least one induction heating element and rolling the ring material between the mandrel roll and the main roll, which is induction-heated.

A method for manufacturing a ring-rolled product forms the ring-rolled product from a ring material by using a mandrel roll and a main roll. The mandrel roll and the main roll are configured so as to contact inner and outer circumferential surfaces of the ring material, respectively, and are configured so as to press the ring material in a radial direction thereof in a state in which the ring material is rotated in a circumferential direction thereof. The method includes a step of rolling the ring material that includes an operation of induction-heating the main roll by at least one induction heating element and rolling the ring material between the mandrel roll and the main roll, which is induction-heated.

A radial/axial ring rolling mill for rolling a ring has an axial rolling device and a radial rolling device. The radial rolling device includes a main roller and a roller mandrel, between which the ring can be shaped. The roller mandrel is retained in the upper region thereof on a mandrel bearing head supported in a first linear adjustment device to be able to be horizontally adjusted in such that the roller mandrel can be moved perpendicularly to the longitudinal extent thereof in the direction towards the main roller and in the opposite direction thereto. The first linear adjustment device together with the mandrel bearing head and the roller mandrel is able to be adjusted as a unit by a second linear adjustment device in a vertical manner so that the roller mandrel can be pulled out of the inner space of the ring and introduced therein.

A radial/axial ring rolling mill for rolling a ring has an axial rolling device and a radial rolling device. The radial rolling device includes a main roller and a roller mandrel, between which the ring can be shaped. The roller mandrel is retained in the upper region thereof on a mandrel bearing head supported in a first linear adjustment device to be able to be horizontally adjusted in such that the roller mandrel can be moved perpendicularly to the longitudinal extent thereof in the direction towards the main roller and in the opposite direction thereto. The first linear adjustment device together with the mandrel bearing head and the roller mandrel is able to be adjusted as a unit by a second linear adjustment device in a vertical manner so that the roller mandrel can be pulled out of the inner space of the ring and introduced therein.

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 method of manufacturing a preliminary formed body includes an ironing step and a thickening step. In the ironing step, a predetermined range of a plate is formed into a tapered shape in such a manner that while rotating the plate, a transform target portion of the plate is locally heated by induction heating, and a processing tool is pressed against the transform target portion. In the thickening step, a peripheral portion that is a distal end of the tapered shape of the plate is expanded inward in such a manner that while rotating the plate, the peripheral portion is locally heated, and a forming roller is pressed against the peripheral portion to push the peripheral portion in a direction orthogonal to a thickness direction of the peripheral portion.