, Description:METHOD AND DEVICE FOR CHECKING COMPLEX END FACE RADIUS OF MILLED GUIDE BLADE FOR STEAM TURBINE RING SEGMENT
FIELD OF THE INVENTION:

[001] The invention is related with the special milled guide blades of steam turbine ring segment blades. More particularly, the present invention is directed to a device and method for checking of complex end face radius of the milled guide blade for steam turbine ring segment.

BACKGROUND OF INVENTION/PRIOR ART:

[002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[003] Steam turbine, comprising power station steam turbine, industrial steam turbine, exhaust turbine etc., is widely used and very important in national economy. Blade is the cardiac component of steam turbine, and manufacture of its complex structure is difficult. The dimensional accuracies and surface qualities of blades are very critical to quality.

[004] The present invention is designed for checking critical radius of end face surfaces of a special milled guide blade for steam turbine ring segment. The end faces of the blades are milled in single setting in CNC 5-axis milling machines. The radius at bottom and top of the blades are welded with matching components named as upper and lower ring segments respectively. Referring to figure 1A for ring segment, for proper matching of blades and consequent fitments, the radii at the end faces of the blades are required to be checked properly.

[005] Mentioned milled ring segment blades are manufactured in CNC 5-axis milling machines from raw material blanks of rectangular cross sections in single setting. The end faces of the blades are also milled to generate required designed radius as shown in Figure 1. The radius is milled at a direction perpendicular to the exit edge plane of the blade. A datum line “L”, collinear with the exit edge plane is shown in Figure 1. The radius “R” as per design in the solid plane is machined by milling. The constant challenge is to check the radius with a device manually with respect to available datum planes and reference features of the job.

[006] Therefore, there exists a need for a device and an associated method for achieving accuracy of measurement in checking end face radius of milled guide blade for steam turbine ring segment because of the geometric complexity.

OBJECTS OF THE INVENTION:

[007] It is therefore a principal object of the present invention to provide a device and method for checking of complex end face radius of the milled guide blade for steam turbine ring segment.

[008] Another object of the invention is to accurately check the radius of the blade with the device manually with respect to available datum planes and reference features of the job.
[009] Still another object of the present invention is to provide a device and method for checking of complex end face radius of the milled guide blade for steam turbine ring segment, which is simple.

[0010] Yet another object of the present invention is to provide a device and method for checking of complex end face radius of the milled guide blade for steam turbine ring segment, which consumes less time.

[0011] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

SUMMARY OF THE INVENTION:

[0012] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.

[0013] This summary is provided to introduce concepts related to a device and a method for obtaining high degree of accuracy in checking complex end face radius of milled guide blade for steam turbine ring segment.

[0014] According to the invention, there is provided a device for checking complex end face radius of milled guide blade for steam turbine ring segment comprising an angle block [A] assembled to a body [B] by a plurality of fasteners [F] for holding the blade that blade end face radii [R] which is along a direction [D] perpendicular to datum line [L], wherein the datum line [L] is collinear with blade exit edge plane [EP] (Ref fig 1, 3, 6).

[0015] Mentioned special milled ring segment blades have an aero foil section followed by profile thickening at end faces (T) as shown in Fig 2. In an aspect, the invented device complies with 2-number of reference features as mentioned above and a plane having the design radius [R] as shown in Figure 6. The blade is rested upon the device with reference to datum planes P1, P2 as shown in Fig 4, 5, 6. After proper placement of the blade in the checking device, there should be no gap or gap within tolerance limit between end face plane and checking plane of device as shown in Fig 4, 5 and 6. The gap as mentioned is checked by feeler gauge.

[0016] The inventive features have been indicated in the principal claim and subsidiary features/steps have been mentioned in the dependent claims.

[0017] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

[0018] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

[0019] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS :

[0020] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:-

Figure 1 shows: the blade features having the end face radius in an embodiment of the present invention;

Figure 1A shows: the fitting of blades in inner and outer ring segments of turbine in an embodiment of the present invention;

Figure 2 shows: isometric views of blade and the thickening at end faces for welding allowance as mentioned above as well as the end face radius to be checked.

Figure 3 shows: the isometric view of the proposed checking device in an embodiment of the present invention;

Figure 4, 5 shows: checking of blade in an isometric view while blade exit edge plane and the edges of pressure side remain butted to angle block in an embodiment of the present invention;

Figure 6 shows: assembly of the checking device in an embodiment of the present invention; and

Figure 7 shows: angle block of the checking device in an embodiment of the present invention.

[0021] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS :

[0022] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

[0023] The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.

[0024] The present invention relates to a device and method for checking of complex end face radius of the milled guide blade for steam turbine ring segment.

[0025] Referring now to accompanied figures in details, in which Figure 1 shows the steam turbine blade features wherein the end face radius [R] of the blade is milled in a direction [D] perpendicular to the exit edge plane [EP] of the blade. A datum line [L] is collinear with the exit edge plane [EP] as shown in Figure 1. The radius [R] as per design in the solid plane is machined by milling. Main objective is to check the radius with a device manually with respect to available datum planes and reference features of the job. Figure 1A shows the fitting of blades in inner [I] and outer ring segments [O] of turbine.

[0026] Now, reference may be made to Figure 6 illustrating assembly of the checking device. The checking device comprises of a body [B] and an angle block [A]. The angle block [A] is assembled to the body [B] with a plurality of fastening bolts [F]. For the angle block [A], reference may be made to Figure 7. The body [B] is having substantially L-section and the angle block [A] is having substantially triangular section. The body [B] is having a horizontal member [H] and a vertical member [V] integrally connected to each other constituting a single piece. The angle block [A] is fitted to vertical member [V] of the body [B] at intermediate part of the vertical member [V].

[0027] The checking device is made of material including Alloy Steel without restricting scope of the invention to the same. Thus, other materials readily apparent to a person skilled in the art are understood to be within purview of the invention.

[0028] Mentioned special milled ring segment blades have an aero foil section followed by profile thickening [T] at end faces a shown in Figure 2. The blade has end face radii [R] as shown in Figure 2, which is along the direction [D] as in Figure 1. The direction [D] is perpendicular to datum line [L] as in Figure 1. The datum line [L] is collinear with the exit edge plane [EP] as shown in Figure 1.
[0029] There are two references used in the instant invention as follows:

[0030] Reference feature 1: The datum line [L] is a reference datum for checking of the blade end radius [R].

[0031] Reference feature 2: The edge line [EL] at the pressure side is at an angle [O] with datum line [L]. The line [EL] is also a reference for checking of the radius [R].

[0032] Figure 2 shows isometric views of blade and the thickening at end faces [T] for welding allowance as mentioned above as well as the end face radius [R], which is to be checked.

[0033] Referring now to Figure 3 and Figure 4, the milled blade is kept in the device in such a way that exit edge plane [EP] of blade remains butted to reference plane [P1] and the edges of pressure side remains butted to plane [P2] of angle block [A]. The end face of the blade rests upon the checking plane as per Figure 6.

[0034] The datum/ reference plane [P1] is on the body and [P2] is on the angle block [A]. The acute angle between [P1] and [P2] is [O] which in other words is the angle between datum line [L] and reference [EL] as per design requirements of the blade as shown in Figure 1.

[0035] The invented system for checking complies with two number of reference features as mentioned above and a plane having the design radius [R] as shown in Figure 6. The blade is rested upon the device with reference to datum planes [P1, P2] as shown in Figure 4, 5, 6. After proper placement of the blade in the checking device, there should be no gap or gap within tolerance limit between end face plane and checking plane of device as shown in Figure 4, 5, 6. The gap as mentioned above should be checked by feeler gauge.

Advantageous Features
- Simple in construction
- Simple method
- Saves time in checking complex end face radius of milled guide blade
- No skilled worker required for implementation of the invention
- Cost effective

Working of the Invention

[0036] Checking complex end face radius of milled guide blade for steam turbine ring segment involves the below steps sequentially:

- placing the blade that exit edge plane [EP] of blade remains butted to reference plane [P1] and the edges of pressure side remain butted to plane [P2] of the angle block [A], wherein the end face of the blade rests upon the checking plane;
- ensuring that there exists no gap or a gap within tolerance limit between end face plane and checking plane of device.;
- ensuring that the blade has end face radii [R], which is along the direction [D] perpendicular to datum line [L] and the datum line [L] is collinear with the exit edge plane [EP];
- checking the gap by a feeler gauge.

Test Result
The blades are checked in process. In case of occurrence of deviation, corrective steps in manufacturing are taken.

[0037] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0038] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0039] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogues to “at least one of A, B and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B”.

[0040] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

[0041] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0042] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[0043] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims:WE CLAIM:

1. A device for checking complex end face radius of milled guide blade for steam turbine ring segment comprising an angle block [A] assembled to a body [B] by a plurality of fasteners [F] for holding the blade that blade end face radii [R] is along a direction [D] perpendicular to datum line [L], wherein the datum line [L] is collinear with blade exit edge plane [EP].

2. The device as claimed in claim 1, wherein the fasteners [F] include bolts and the device is made of material including Alloy Steel.

3. The device as claimed in claim 1 or 2, wherein the body [B] is having substantially L-section and the angle block [A] is having substantially triangular section, in which the body [B] is having a horizontal member [H] and a vertical member [V] integrally connected to each other constituting a single piece.

4. The device as claimed in claims 1-3, wherein the angle block [A] is fitted to vertical member [V] of the body [B] at intermediate part thereof.

5. The device as claimed in claims 1-4, wherein the device for checking complies with two reference features and a plane having the design radius [R] wherein the first reference feature of a datum line [L] as a reference datum for checking of the blade end radius [R] and a second reference feature of an edge line [EL] at the pressure side at an angle [O] with datum line [L] and the edge line [EL] is a reference for checking of the radius [R].

6. The device as claimed in claims 1-5, wherein the datum/ reference plane is on the body [B] and on the angle block [A], in which the angle between [P1] and [P2] is the angle between datum line [L] and milling direction along radius [D] as per design requirements of the blade.

7. A method of checking complex end face radius of milled guide blade for steam turbine ring segment using the device as claimed in claim 1, comprising steps of:
- placing the blade that exit edge plane [EP] of blade remains butted to reference plane [P1] and the edges of pressure side remain butted to plane [P2] of the angle block [A], wherein the end face of the blade rests upon the checking plane;
- ensuring that there exists no gap / a gap within tolerance limit between end face plane and checking plane of device.;
- ensuring that the blade has end face radii [R], which is along the direction [D] perpendicular to datum line [L] and the datum line [L] is collinear with the exit edge plane [EP];
- checking the gap by a gauge.