Claims:WE CLAIM:

1. A device for alignment and assembly of spring in turbo generators comprising of a clamping assembly (10) and a locking fixture (20), wherein
the clamping assembly (10) comprising of a channel (12), the channel (12) includes a substantially U-portion (14) having a hole at the center of base 13 and the U-portion 14 is welded at the top of base (13) of the channel (12), a threaded means (11) is fitted within the hole in the base (13) of the channel (12) of the clamping assembly, one side of the U-portion (14) is provided with a hole to accommodate threaded means including a screw (15); and
the locking fixture (20) comprises of a base plate (22) having a chamfer at each corner, in which a block (23) is welded at both distal ends of said plate (22) and a hole is provided at the center of the block (23) through which threaded screw (21) passes.

2. The device for alignment and assembly of spring in turbo generators as claimed in claim 1, wherein the threaded means including a screw (11) is provided in the clamping assembly (10) of the device.

3. A method of operating the device for alignment and assembly of spring in turbo generators as claimed in claim 1, wherein the method comprising steps of:
- fitting the locking fixture (20), in between the Spring (30) and wall of the turbo generator while the spring (30) hangs with the boss of stator frame;
- fitting clamping assembly (10) at the bottom of Spring (30);
- inserting in this spring position, the locking fixture (20) from the top and in between spring (30) and stator frame that the free end of the threaded means (21) butts with the stator frame while the plate (21) of the locking device (20) longitudinally butts with the spring neck (31);
- adjusting individually the threaded means (21) to provide the parallelity to the spring with respect to the centreline;
- providing an equal rotary input to the threaded means (21) to adjust the distance of the Spring (30) from the stator frame centerline;
- affixing clamping assembly (10) with the spring boss assembly end using the screw (15);
- rotatably operating the threaded means (11) including screw to move the spring end to align the spring.

4. The method of operating the device for alignment and assembly of spring in turbo generators as claimed in claim 3, wherein the Spring (30) is hangingly placed with stator frame that firstly, it is supported temporarily to sustain the weight of the spring and secondly, the boss of the stator and the spring eye (32) matches; in this spring position, the locking fixture (20) is inserted from the top in between spring (30) and stator frame that the free end of the threaded means (21) butts with the stator frame while at the same time the plate (22) of the locking device (20) longitudinally butts with the spring neck (31), which results in a movement of the spring in two ways, First, the threaded means (21) is individually adjusted to give the parallelity to the spring with respect to the centreline and Second, once the parallelity is achieved, both the threaded means (21) are given equal rotary input to provide a linear movement of the entire spring, forward or backward, so as to adjust the distance of the Spring (30) from the centerline of the stator frame.

5. The method of operating the device for alignment and assembly of spring in turbo generators as claimed in claim 4, wherein as the spring (30) moves concentrically in the stator frame boss, the forward or backward movement of the spring is resisted by the surface friction, which tends to result in a differential movement of the two spring ends, the spring end fitted in the boss tends to move less with respect to the free end of the spring;
the Spring (30) is hanged with the boss of stator frame and locking fixture (20) is fitted in between the Spring (30) and the wall of the turbo generator, the clamping assembly (10) is fitted at the bottom of Spring (30) with spring and affixed with the spring with screw (15) of the clamping assembly (10), the threaded means (11) of clamping assembly (10) is rotatably operated to align the spring, in order to meet the alignment specification, the threaded means (21) is rotatably operated to achieve the distance and to maintain parallelity of the spring.
, Description:A DEVICE FOR ALIGNMENT AND ASSEMBLY OF SPRING IN TURBOGENERATORS AND A METHOD THEREOF

FIELD OF THE INVENTION:
[001] The present invention relates to electric generators, and more specifically, to a device for accurate alignment and assembly of spring of the spring mounting system supporting a stator core within a stator frame of such generators.

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] Turbo Generator of various capacities ranging from 210 MW to 1000 MW are manufactured worldwide by many OEMs. This generator is a major product of Thermal Power Stations. The Turbo Generator consists of two main parts, one is Stator (Static) and another is Rotor (rotating).

[004] The rotor rotates in the annular space within the stator core. Stator Core is one of the major components of Stator with main function of providing path to the rotating flux produced by the rotation of rotor in turbo generator. For exemplary reference, length of core of a large size turbo generator can reach be up to 6500 mm and the weight of approximately 320 tons.

[005] As the rotor of the turbo generator rotates, its magnetic field also revolves in unison with the rotor. This rotating magnetic field exerts a cyclical force on the generator's stator core. This force, in turn, causes vibrations to occur in the core which are of concern in such high speed, high power machines. The vibrations are transmitted through the frame to the generator foundation via some attachment points such as plate type springs. The magnitude depends upon the degree of isolation incorporated in the design of the support system.
[006] Springs are aligned with respect to the centreline of the stator frame. Once the alignment is done correctly, the springs are welded in the stator frame to lock it in the aligned position.

[007] There is plurality of springs that are assembled inside the stator frame by welding. Left and right side springs are assembled in vertical position whereas bottom springs are assembled in horizontal position. During assembly alignment of spring is done. For alignment of springs, a piano wire is passed through the center of the stator frame. Distance of the face of the spring from the stator core center line is maintained during alignment. Also parallelity of the spring is maintained with respect to the stator centreline.

[008] The inadequate or improper alignment of the springs resulting from those known techniques are due to the need to have considerable stiffness between the stator and the casing. It is therefore necessary to have proper alignment of the springs in order to take up the forces of the rotary electric machine so as to prevent major eccentricity between the rotor and the stator. Major eccentricity can give rise both to an increase in the amplitude of the vibration and to the stator sticking to the rotor.

[009] As per prior art, taper wedges and clamps were used for the process of alignment of the spring. Clamp loosely and temporarily holds the spring in position which is in alignment to the centreline of the stator frame and taper wedges are adapted to fit between the spring and the wall of the stator frame. These wedges were required to be hammered for them to slide and achieve the required alignment reading. However, if springs are needed to be moved outward, the wedges need to be loosen. During loosening of the wedges, it tends to fall disturbing the setting of the spring and thus requiring the alignment process to be repeated ab-initio.

[0010] Various constraints were noticed during the process listed herein below:
- Longer time required for assembly,
- more power consumption,
- more man power required to complete the job,
- less safe for workman,
- higher fatigue.

[0011] Basic constraint in developing the fixture for alignment of spring in the generator stator was to make a structure which can provide the necessary variable movement of the spring during alignment process of spring. To overcome the constraints, the present invention of the fixture is designed. To resolve the issues in prior art, the present invention proposes a device for alignment and assembly of spring in a large size turbo generator.

OBJECTS OF THE INVENTION:
[0012] Primary object of the invention is to propose a device for alignment and assembly of spring in the large size turbo generator including turbo generator of 600/660/800 MW with respect to the centreline of the stator frame and a method thereof.

[0013] Another object of the invention is to propose a device for alignment and assembly of spring in the large size turbo generator and a method thereof, which obviates shortcomings of the prior art (s).

[0014] Yet another object of the invention is to propose a fixture for alignment and assembly of spring in the large size turbo generator, which is simple in construction.

[0015] Still another object of the invention is to propose a fixture for alignment and assembly of spring in the large size turbo generator, which works efficiently.

[0016] One another object of the invention is to propose a device for alignment and assembly of spring in the large size turbo generator including turbo generator of 600/660/800 MW that provides easy access so that springs are welded in the stator frame to lock it in the aligned position.

[0017] Still one another object of the invention is to propose a device for alignment and assembly of spring in the large size turbo generator including turbo generator of 600/660/800 MW so as to prevent a major eccentricity between the rotor and the stator.

[0018] Yet one another object of the invention is to propose a device for alignment and assembly of spring in the large size turbo generator including turbo generator of 600/660/800 MW which can provide the necessary variable movement of the spring during alignment process of spring.

[0019] 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:
[0020] 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.

[0021] According to this invention, there is provided a device for alignment and assembly of spring in turbo generators comprising of a clamping assembly (10) and a locking fixture (20), wherein the clamping assembly (10) comprising of a channel (12), the channel (12) includes a substantially U-portion (14) having a hole at the center of base (13) and the U-portion (14) is welded at the top of base (13) of the channel (12), a threaded means (11) is fitted within the hole in the base (13) of the channel (12) of the clamping assembly, one side of the U-portion (14) is provided with a hole to accommodate threaded means including a screw (15); and the locking fixture (20) comprises of a base plate (22) having a chamfer at each corner, in which a block (23) is welded at both distal ends of said plate (22) and a hole is provided at the center of the block (23) through which threaded screw (21) passes.

[0022] 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.

[0023] 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.

[0024] 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:
[0025] 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 illustrates: Isometric view of a clamping assembly of the present invention.
Figure 2 illustrates: Isometric view of a locking fixture according to the invention.
Figure 3 illustrates: A method of preparing and using the clamping assembly and locking fixture for alignment of spring in accordance with the invention.

[0026] 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.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S) OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:

[0027] 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.

[0028] The present invention makes a disclosure regarding a technology pertaining to a device for alignment and assembly of spring in the large size turbo generator including turbo generator of 600/660/800 Mega Watt and a method thereof.

[0029] Now, reference may be made to Figure 1 indicating Clamping assembly (10) comprising of U-channel (12). The channel (12) includes a substantially U-portion (14) having a hole at the center of base (13) and the U-portion (14) is welded at the top of base (13) of the channel (12). Threaded means such as a screw (11) is used in the clamping assembly (10) of the fixture. This screw (11) is fitted within the hole in the base (13) of the U channel (12) of the clamping assembly. The threaded means (11) is used to align spring (30) during assembly of the spring (30). One side of the U-portion (14) is provided with a hole to accommodate threaded means including a screw (15).

[0030] Referring to Figure 2, wherein Plate (22) forms base of the locking fixture (20). The plate (22) has a chamfer at its all corners. A block (23) is welded at both distal ends of said plate (22). There is a hole provided at the center of the block (23) through which threaded screw (21) can pass.

[0031] Using the locking fixture (20) and clamping assembly (10), along with the method as discussed below, the springs can be aligned accurately and in a very short time.

[0032] Now, reference may be made to Figure 3. Spring (30) is hangingly placed with stator frame in such a way that firstly, it is supported temporarily to sustain the weight of the spring and secondly, the boss of the stator and the spring eye (32) matches. In this spring position, the locking fixture (20) is inserted from the top in between spring (30) and stator frame in such a way that the free end of the threaded means (21) butts with the stator frame while at the same time the plate (22) of the locking device (20) longitudinally butts with the spring neck (31). This results in a key movement of the spring in two ways. First, the threaded means (21) can be individually adjusted to give the required parallelity to the spring with respect to the centreline. Second, once the parallelity is achieved, both the threaded means (21) can be given equal rotary input to provide a linear movement of the entire spring, forward or backward, so as to adjust the distance of the Spring (30) from the centerline of the stator frame.

[0033] However, as the spring (30) moves concentrically in the stator frame boss, the forward or backward movement of the spring is resisted by the surface friction. This tends to result in a differential movement of the two spring ends. The spring end fitted in the boss tends to move less with respect to the free end of the spring. In this case, there will be a tilt in the spring with respect to the centreline. This tilt disturbs the parallelity of the spring.

[0034] While the Spring (30) is hanged with the boss of stator frame and locking fixture (20) is fitted in between the Spring (30) and the wall of the turbo generator, the clamping assembly (10) is fitted at the bottom of Spring (30) with spring and affixed with the spring with screw (15) of the clamping assembly (10). The threaded means (11) of clamping assembly (10) is rotatably operated to align the spring. In order to meet the alignment specification, the threaded means (21) is rotatably operated to achieve the distance and to maintain parallelity of the spring.

Working of the Invention:
[0035] A method for operating the device for alignment and assembly of spring in large size turbo generators comprising of steps as follows:
Step-1: fitting locking fixture 20, in between the Spring 30 and the wall of the turbo generator while the spring 30 hangs with the boss of stator frame;
Step-2: fitting clamping assembly 10 at the bottom of Spring 30;
Step-3: inserting in this spring position, the locking fixture 20 from the top and in between spring 30 and stator frame in such a way that the free end of the threaded means 21 butts with the stator frame while at the same time the plate 21 of the locking device 20 longitudinally butts with the spring neck 31;
Step-5: adjusting individually the threaded means 21 to provide the required parallelity to the spring with respect to the centreline;
Step-6: providing an equal rotary input to threaded means 21 to adjust the distance of the Spring 30 from the stator frame centerline;
Step-7: affixing clamping assembly 10 with the spring boss assembly end using screw 15;
Step-8: rotatably operating threaded means 11 to move the spring end to align the spring.

Advantageous Features:
Achievement of Higher accuracy in alignment of spring in less time;
Improved Productivity and Quality;
Less time consuming.

Test Result:
[0036] The device has been put for use mechanically in our machine shop. Desired alignment and assembly results are achieved using the same.

[0037] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other cast structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions.

[0038] 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.

[0039] 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.

[0040] 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”.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.