DE2235961A1 - TURBINE ROTOR - Google Patents

Description

Dipl.-Ifif. Dipl. PbL DfSTRICH LEVYiNSKY July 21, 1972

PATENT APPLICATION 8 mouths 21 - Gotthordsfr. SI

Telephone S61762

7133 - V

Societe Generale de Constructions Electriques et Mecaniques (ALSTHOM)

Paris 16eme, 38, avenue Kleber (France)

"Turbine rotor"

Priority of July 23, 1971 from French patent application 71/27 204

The invention relates to a turbine rotor and in particular to a rotor for a steam or gas turbine .

The advancement of turbines; especially from

Steam turbines with the aim of achieving ever greater outputs lead to an increase in the weight of the rotors, which in turn an increase in forces, such as those acting on the conditions dynamic forces, the changing bending stresses during the rotational movement, those that occur continuously or temporarily thermal stresses, which consequently give rise to problems with regard to the strength of the shaft, the critical Derive flexion speeds, etc.

It is therefore essential to reduce the weight of the rotors as much as possible to restrict.

In the case of turbine rotors consisting of one piece for very high outputs, those at the drop forge To make working holes in the axis of parts of a very large diameter in order to ensure the homogeneity of the used To check the material. This results unintentionally

309811/0661

a certain reduction in weight, but since the bore engages the most heavily loaded parts of the rotor in the same way as the others, there is thus an increase in the stresses in the rotor. The rotors formed by a row of solid disks, which may be provided with an axial opening that runs through the entire grouping, can be made easier by reducing the thickness of the disks in their central part, but the weight loss achieved is only insignificant.

The aim of the invention is therefore to create a turbine rotor of a new concept, the one large leeway in the dimensioning of the individual parts of the rotor shaft while allowing the weight to be taken into account to limit the mechanical properties of the material used to the necessary minimum. This rotor will characterized in that it is at least partially formed by an axial sequence of rings welded together, the inside diameter and radial thickness of which change in opposite directions from one ring to the other according to the forces exerted by the respective ring Ring is exposed during operation of the turbine.

It proves to be particularly advantageous here to choose the dimensions of the rings in such a way that the occurring Forces in the individual rings are evenly distributed and are close to the permissible limits of use of this Move materials that form rings.

If the turbine is working with a variable medium, and in particular a steam turbine, the strongest forces in the last expansion stage. According to the invention there is an axial sequence of the above-described blade rings assigned to the first stages of a relaxation or expansion of the variable medium and this axial sequence of rings on a solid disk with blades is welded, which forms the final stage of this expansion process.

In the further course, based on the attached scheme

309811/0661

Drawing a non-restrictive, according to the invention Embodiment described.

- Figure 1 - thus shows a double-flow steam turbine rotor in longitudinal section, the blades are not shown.

The bidirectional flow of steam occurs in the central part of the Rotor at 1 a. A first flow flows through the rotor from left to right and is thus successively via the (not shown) Blades of the rings 2, 3 and 4 and a solid disk 5, which is welded to the end of a shaft section 6. In in the same way a second stream of steam flows through the rotor of right to left and is thus successively over the blades (not shown) of the rings 7, 8 and 9 and a solid disk 10 which is welded onto the end of a shaft section 11

The individual rings 2, 3, 4, 7, 8, 9 and the solid discs 5 and 10 form the elements of a unit, which is achieved by the welded joints such as 12 along the adjacent surfaces of the elements that make it up.

The number of rings such as 2, 3, 4 or 7, 8, 9 corresponds to the number of stages or expansion stage groups that the turbine includes minus the last stage to which a solid disk 5 or 10 is assigned. The inside diameter and the Radial thickness of each of these rings are chosen in such a way that under the action of centrifugal forces and temperatures the displacement at the level of the welded connections such as 12 corresponds to that of the adjacent part. The inside diameter of a The ring is the bigger and therefore the weight saving all the more significant, the closer this ring is to the steam inlet, since the forces occurring in the rotor from the upper to the lower part of the expansion sr aumes to increase. The inner diameter thus decrease from ring 2 to ring 4 and from ring 7 to ring 9.

The solid disks 5 and 10 are forged, although these are not drilled open in the example shown, that of a turbine rotor corresponds to a very high performance, with the possibility of

- 4 3 0 98 Π / 06-6Ί

the starting material can be used to the full. In other applications, however, these disks 5 and 10 could be a medium one Have bore in those cases where the forces involved made this possible. These full disks 5 and 10 have directed outwards to the group of rings and washers axial extensions 13 and 14 for the connections and supports for the shaft and the arrangement of sealing members, not shown.

In the rotor shown are the forces that occur

evenly distributed and adjusted to the greatest possible value that occurs in the last expansion stage. The rotor is thereby brought to its greatest possible use value that the materials forming the individual elements are evenly down to their permissible application limits are claimed.

A rotor constructed in this way is brought to a minimum weight, taking into account the permissible limits and also has numerous advantages such as better rotation behavior due to greater rigidity, higher speeds for critical flexion values, lower dynamic effect on the support elements, static bending value and changing Flexion load below the previous limits and minimal thermal stress.

If the turbine is working with only one flow, the rotor would only consist of parts 11, 2, 3, 4, 5 and 6 exist, with parts 11 and 2 being welded together and parts 10, 9, 8 and 7 omitted.

If the turbine rotor is working with more than two flows, it would at least be part of it of the rotor shown for the double flow or such according to the variant explained for one flow.

309811 / 0K61

Claims (3)

IWpl.-lng. Dipl. <Mc. p * bl. ^ DIETRICH LEWINSKY,. , ".", PATENT LAWYER 2'JUl! WC 8Μβκ! * Η21 - 6otftordjtr. 81 7133 - ν Telephone 561743 Societe Generale de Constructions Electriques et Mecaniques (ALSTHOM)
Paris 16eme, 38, avenue Kleber (France) Patent claims: (1. yrurbinenrotor, characterized / that this is at least ^ - ^ partially formed by an axial sequence of rings welded together (2,3,4, 7,8,9), the inner diameter and radial thickness of which are opposite from one ring to the other Change the ring according to the forces that the ring in question is subjected to during operation of the turbine. 2. Turbine rotor according to claim 1, characterized in that the dimensions of the individual rings (2,3,4, 7,8,9) are selected in the form are that the forces occurring in the rings are evenly distributed and are close to the permissible limits of use move the materials forming these rings. 3. Turbine rotor for a variable medium according to one of the claims 1 or 2, characterized in that such a sequence of axially aligned blade rings (2,3,4, 7,8,9) the forms the first stages of an expansion of the variable medium and that this sequence against one equipped with blades Solid disk (5, 10) is welded, which forms the last stage of this expansion process. 3098 Π / 0R61 Blank page