JPS63501372A - Method for determining the shape of side-entry turbine blades that can be designed using scale models - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Tosho Emperor's Fortress Manufacturing method for side-entry turbine blades that can be designed using proportional scales Related applications This application is a continuation in part of Application No. 067780.387 dated July 30, 1985. A contract between Eschinghouse Electric Corporation and the Department of Defense. Pursuant to Contract No. N00024-79-C-4175, the United States Government have the right to

Oimu Ω money transfer The present invention relates to the roots of steam turbine blades, and more particularly to the roots of side-entry turbine blades. , relating to the method of manufacturing grooves and tower-shaped parts. Side entry type turbine blades are Christmas tree The disk forming the rotor of the turbine has a Lee-shaped root and corresponds to said root. Under centrifugal load and bending load of 0g, the base is fitted into the groove formed so as to Specific geometries have already been developed that contribute to reducing stress concentrations as much as possible. It is possible to design on a proportional scale over a range of sizes.

Toyonu Osudan A book that can equalize the stress concentration at the root and tower part of each wing The method of manufacturing the roots, towers and grooves of the turbine blade according to the invention is such that they have the same shape. forming the root, groove and tower part of the blade, and being the only contact area between the blade and the tower part. The root and tower-like parts of the blade are formed so as to have sloped surfaces. Create a proportional dimension model of the part and multiply all dimensions in said model by a constant From this dimensional model, the root, tower, and groove of any size can be created by It is characterized by being able to be designed and manufactured using a proportional scale.

ward national prisoner ndanj The objects and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. It will be. In the accompanying drawings: FIG. 1 shows the roots of a turbine blade manufactured according to the invention. 1 is a partial cross-sectional view of a turbine disk showing the base, grooves and tower section; FIG.

FIG. 2 is a proportional dimensional model of the root and tower portion of a blade manufactured according to the present invention. FIG.

A dry day on the river side With detailed reference to FIG. This shows a part of Section 5. The wing root 3 has tongues 9.11, one on each side. have The tongues 9.11 each have an inclined surface 13.15. Same as wing root 3 A full 7 of the same shape forms a tower-shaped portion 17 which also has the same shape as the root 3 of the blade. tower-shaped part The portion 17 has tongues 19.21, one on each side thereof, the tongues 19.21 being inclined. Each has an inclined surface 23.25 that engages surface 13.15. Only this retention part This is the contact area between the blade root 3 and the tower-shaped portion 17.

The blade root 3, groove 7 and tower portion 17 are subject to stress concentration due to centrifugal and bending loads. exhibiting the same shape designed to help reduce as much as possible. this shape The shapes can be designed to scale over a range of sizes. stated here A side-entry turbine blade that can be designed using a proportional scale with two tongues. The root geometry reduces stress concentrations caused by centrifugal and bending loads to existing designs. Significant reduction in comparison. An important improvement is to adjust the ratio of the inner and outer diameters adjacent to the sloped surface. The reason is that it is set to 2, whereas in the previous design it was set to 1. Set the ratio like this So by equalizing the stress at all stress concentration points the material becomes more It can be used effectively. As a result of finite element stress analysis, the maximum stress is determined by centrifugal load. It was found that the bending load could be reduced by 28% and the bending load by 30%.

The manufacturing methods for the root 3, groove 7, and tower-shaped portion 17 of the side entry type turbine blade are all The blade root 3, groove 7, and tower-shaped portion 17 are formed so that they have the same shape, and The wing roots 3 and 19.21 are arranged so that they are provided with tongues 9.11 and 19.21, one on each side. and a tower portion 17, with only the sloped surfaces 13.15 and 23.25 of each tongue forming a wing. This is the contact area between the root 3 and the tower-shaped part 17, and the line perpendicular to the blade root center line at an angle of approximately 25°, ensuring that all stress in the root and tower section of the blade is The first step is to form the root and tower-shaped parts of the blade, where the stress at the point of force concentration is equalized. Create the proportional dimension model shown in Figure 2, and calculate the radial distance between the centers of the blade root inclined contact surface. is set as a constant value C, and the center of the radially outer inclined contact surface is set at 0.0 from the root center axis. 6203C, and the center of the radially inner contact surface is 0.3797 from the root center axis. G, and set the center of the radially inner inclined surface to 0.49 from the radially inner end of the root of the wing. By setting it to 90C and setting the other dimensions to 0 times the number shown in Figure 2, Fabricate one set of blade roots, grooves and towers and measure perpendicular to the blade root centerline. equal to the distance between the centers of the inclined surfaces, and at the center position of the radially inner inclined surface. By changing the constant C, which is approximately equal to the distance between the center line of the tower-like part and the center line of the root of the wing, Even if the root and tower-like parts of the blades are expanded or contracted proportionally, each set ensuring that all stress concentration points within the wing roots and towers are equalized; Consists of.

Claims (5)

[Claims] 1. Form the root, groove and tower-like part of the blade so that they have the same shape, and the blade and the tower-like part The root and tower-shaped portions of the blades are formed so that they have sloped surfaces that are the only contact area between the Then, create a proportional dimension model of the blade root, groove, and tower-like part, and All dimensions equal to the distance between the slopes measured perpendicular to the centerline of the wing root. From this dimensional model by multiplying by a constant The base of each wing The construction of the roots, towers and grooves of turbine blades to equalize the stress concentration in the towers. Law. 2. from the model by forming an inclined contact surface at a constant angle on the model. The root, groove and tower parts of each wing of any set of wings designed by proportional scale. characterized in that it also includes the step of equalizing the stress concentration in the root and tower-shaped parts. A method according to claim 1. 3. the root of the wing, each having tongues on each side, each having an inclined contact surface; The method according to claim 2, characterized in that the method also includes a step of forming a tower-shaped portion. Law. 4. characterized in that it also includes the step of setting the ratio of the inclined surface to the adjacent radius to approximately 2. The method according to claim 1. 5. The tower-shaped portion at the center of the radially inner inclined surface and the root of the blade adjacent thereto The method also includes the step of setting a distance between center lines of The method according to claim 1.