Description:‘FIXTURE FOR MACHINING SEAL BODY OF A LARGE SIZE TURBO GENERATOR’

FIELD OF THE INVENTION:
The subject matter disclosed herein relates to the art of hydrogen cooled generators and, more particularly, to a fixture or a work holder for supporting the turbogenerator seal body and also aid in its proper clamping during machining while being mountable on a machine table.

BACKGROUND OF THE INVENTION:
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.

Work holders and fixtures have been employed heretofore to facilitate the proper and rigid clamping and machining of objects at different planes. However, several devices of the prior art have not proven entirely satisfactory in as much as they are complicated in design and construction, expensive to manufacture, and difficult to use.

As an example, present invention is described for a turbogenerator Seal Body in which due to its complex structure /profile and requirement of precise machining, a lot of difficulties are encountered during clamping and machining.

A generator driven by turbine which is used for conversion of mechanical energy to electrical energy, wherein stator frame, rotor, end shield, seal body are the main components of turbogenerator.

Most important design criteria of a generator are class of insulation used and dissipation of heat generated due to copper loss and core loss. Even class of insulation is based on the heat sustainability of insulation. To improve the heat dissipation, generator is filled either by Hydrogen (higher rating machine) / Air (low rating machine) at more than atmospheric pressure.

A hydrogen-cooled turbo generator is a turbo generator with gaseous hydrogen as a coolant. Hydrogen gas is circulated in a closed loop to remove heat from the active parts then it is cooled by gas-to-water heat exchangers.

In order to prevent the escape of hydrogen from the turbogenerator, seal bodies are used. For obvious reasons, a high level precision is required to be maintained while machining these seal bodies. However, a lot of problems are encountered by the operators in the same owing the complexity in the design and the preciseness of the machining.

Several issues like marking, job setting, rework arising out of machining vibrations, low and restricted material removal rates to maintain vibratory limits, lower feed and rpm parameters, chattering and poor surface finish in holes and pockets away from clamp / support.

In order to eliminate above problems, there exists a need for a work holder fixture for machining of Seal Body.

OBJECTS OF THE INVENTION:
An object of the present invention is to provide universally adjustable work holder / a jig fixture which eliminates the disadvantages of the previously existing system of machining seal body of a large size turbogenerator.
Another object of the present invention is to provide universally adjustable work holder / a jig fixture which is simple in design and construction, cost effective to manufacture, easy to use, and easy to adjust.

Yet another object of the present invention is to provide universally adjustable work holder / a jig fixture which is adaptable relative to the work piece holding portion to support the machining at any desired compound angle thereto.

Still another object of the present invention is to provide universally adjustable work holder / a jig fixture which can be integrated with any standard machine bed without much major modifications.

Still further object of the present invention is to provide universally adjustable work holder / a jig fixture which is extremely inexpensive so that the device of the invention is readily available to small shops and individuals.

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:
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.
According to the present invention, there is provided Fixture for machining seal body of a large size turbo generator constitutes a semicircular piece having two faces [A, B], each of which comprising of a slot [1] and a stopper collar [2], in which the collar [2] fits into T-slot of a standard machine table and automatically aligns the joint face of the seal body [W], a plurality of holes [3] in the fixture [F] at a common PCD of the seal body [W], multitude of holes [4] provided for assembly of clamps for clamping seal body [W] at a plurality of locations, counter holes [5] with counter diameter for passing of clamping bolts for clamping of the fixture [F] on T slot of machine table and multiple holes [6] for lifting of the fixture [F].

The Fixture comprises of a face ‘A’ provided for machining of seal body of large rating generator sets of the likes of 660 to 800 MW and another face ‘B’ designed for machining of seal body of 500 and 600 MW turbo generator, in which both the faces ‘A and B’ are identical except the slot [1] for which depth is different for both the faces A and B.

The seal body [W], extruded collar [11] of which snugly fits into the slot [1] of the fixture [F], which provides support to the seal body [W] while allowing the rotary degree of freedom to the work piece seal body [W while remaining in the slot [1] and this helps in rotating the job [W] in the slot [1] of the fixture [F], if required.

The stopper collar [2] serves functions including One, it gets fit into T-slot of a standard machine table as it is extruded and two, automatically aligns the joint face of seal body when the joint face [12] of seal body [W] touches the said stopper collar [2] thereby eliminating the need for dialing and truing the joint face [12] of seal body [W].

While using one face [A] of fixture [F] for holding seal body [W], the stopper collar [2] in face [B] gets fitted into T slot of machine table and the stopper collar [2] of face [A] automatically aligns the joint face of seal body, and while using other face [B] of the fixture [F] for holding seal body, the stopper collar [2] in face [A] gets fitted into T slot of machine table and the stopper collar [2] of face [B] automatically aligns the joint face of the seal body.

The holes [3] save the fixture from getting damaged while drilling holes at same PCD in seal body and the fixture holes [3] axis aligned with the axis of the job [W] which in turn is aligned with the axis of the drill bit.

The plurality of holes [4] are provided on the fixture [F] wherein the necessary clamps are equipped to hold the job [W], in which the position of the clamps is between every consecutive hole [3,13] and the other adjacent holes [4] are for assembly of bolts which act as support for the clamps.

The holes [6] on face [A, B] are provided for lifting of fixture, alternatively the fixture with job through eye bolts with the help of overhead EOT crane and other set of at least two holes [6] on side face of the fixture [F] is for over turning of fixture through eye bolts i.e. for switching from one face [A] to another face [B] and vice versa.

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.

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.

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:
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 depicting Generator seal oil system and functioning of seal body in hydrogen cooled turbogenerator, indicating the below features:
101
H2 Seal
102 Hydrogen at positive pressure no air can enter

Figure 2 depicting Generator seal oil system and functioning of seal body in hydrogen cooled turbogenerator, indicating the below features:
201 Hydrogen filled generator
202 Seal rings
203 Vacuum Tank
204 Oil Cooler
205 Filter
206 Vacuum Pump
207 Main Seal oil Pump

Figure 3 depicting Generator seal oil system and functioning of seal body in hydrogen cooled turbogenerator, indicating the below features:
301 Oil Flow
302 Seal casing/Seal Body
303 Gas Side
304 Air Side
305 Spring
306 Inner Oil Deflector
307 Gas Side Seal Ring
308 Clearance Rotor
309 Air Side Seal Ring

Figure 4 representing a 3-dimernsional view of a turbogenerator seal body.

Figure 5 showcasing a 3 dimensional view of face-A of the proposed fixture for machining of seal body.

Figure 6 showcasing a 3 dimensional view of face-B of the proposed fixture for machining of seal body.

Figure 7 showcasing a photographic view of the proposed fixture for machining of seal body.

Figure 8 showcasing a photographic view of seal body placed on proposed fixture while the extruded portion of seal body is inserted inside groove of fixture.

Figure 9 showcasing a photographic view of machining of seal body using proposed fixture.

Figure 10 showcasing a photographic view of machining of seal body using proposed fixture.

Figure 11 representing a 3-dimernsional view of a turbogenerator seal body.

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

Before describing in detail, universally adjustable work holder and in accordance with the present invention, it should be observed that the present invention resides primarily in a novel and non-obvious combination of hardware elements and method steps. Accordingly, these elements and steps have been represented by conventional elements and steps in the drawings, showing only those specific details that are pertinent to the present invention so as not to obscure the disclosure with details that will be readily apparent to those skilled in the art having the benefit of the description herein.
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.

The present invention makes a disclosure regarding a technology pertaining to Fixture for machining seal body of a large size turbo generator.

Referring now to figure 1, generator seal oil system and functioning of seal body in hydrogen cooled turbogenerator is shown wherein the heat dissipating medium hydrogen is being contained in a closed loop using a seal body at both ends. The seal oil unit circuit and seal rings is also shown in figure 2 and 3 respectively. It is understood that Seal Body being a very critical component of turbo-generator assembly, every dimension of the it is very important for proper functioning of the machine. In order to prevent escape of hydrogen from the turbogenerator it is essential to provide shaft seals at both ends where the shaft extends through casing.

This is achieved by providing radial oil films in the system, the oil being kept at a higher pressure than that of hydrogen inside the generator. The location where the rotor shaft passes through the stator casing is provided with radial or ring type seal rings. The seal ring is formed by joining two semi-circular rings. Babbitt material is a composition of tin, antimony and copper. The seal ring is lined with Babbitt metal on the shaft journal side. Babbitt metal has a low melting temperature to safeguard the shaft in case of oil starvation.

The seal oil is supplied to the sealing gap from these seal body via radial holes and annular groove in the seal ring. The two half of the seal ring are guided in the seal body, which is bolted on the end shield. To ensure effective sealing the seal oil pressure in the annular gap is maintained at 1.5 KSC (or kilograms per square centimeter) above the gas pressure within the Generator casing. The oil drained on the hydrogen side and air side of the seal rings is through drains in the seal body and sealing cover respectively. On the air side ring relief oil is supplied at 0.5 KSC above the seal oil pressure laterally to the seal ring via an annular groove. Figure 5,6 shows schematic diagram of machine table mountable work holder ‘F’ for machining of Seal Body ‘W’ in accordance with present invention.

Now, reference may be made to Figure 5,6, wherein like numerals refer to like and corresponding parts throughout. Here, the work holding fixture [F] is disclosed to illustrate the invention.

A machine table mountable work holding fixture [F] for machining of seal body, said work holder fixture [F] comprising of a face say ‘A’ of fixture [F] is designed for machining of seal body of large rating generator sets of the likes of 660 to 800 MW, while other face, say ‘B’ is designed for machining of seal body of 500 and 600 MW turbogenerator. Both the faces [A] and [B] of fixture are identical except the slot [1] for which depth are different for both faces [A] and [B].

As shown in figure 11, The extruded collar [11] of seal body [W] snugly fits into the slot [1] of fixture [F], which provides full support to seal body while allowing the rotary degree of freedom to the work piece seal body while remaining in the slot [1]. This helps in rotating the job [W] in the slot [1] of the fixture [F], if required.

As shown in figure 5 and 6, There is a stopper collar [2] which primarily serves couple of intended functions. One, it gets fit into T-slot of a standard machine table as it is extruded and two, automatically aligns the joint face of seal body when the joint face [12] of seal body [W] touches the said stopper collar [2] thereby eliminating the need for dialing and truing the joint face [12] of seal body [W].
While using one face say [A] of fixture [F] for holding seal body, the stopper collar [2] in face [B] gets fit into T slot of machine table and the stopper collar [1] of face [A] automatically aligns the joint face of seal body. Similarly, while using other face say [B] of fixture [F] for holding seal body, the stopper collar [2] in face [A] gets fit into T slot of machine table and the stopper collar [2] of face [B] automatically aligns the joint face of seal body.

There is a plurality of holes [3] in the fixture [F] at a common PCD of seal body [13]. The purpose of these holes is to save the fixture from getting damaged while drilling holes at same PCD in seal body. In a preferred configuration, the fixture holes [3] axis aligned with the axis of the job [W] which in turn is aligned with the axis of the drill bit.

There is plurality of holes [4] provided on the fixture F wherein the necessary clamps shall be equipped to hold the job [W]. Additionally these plurality of holes [4] are provided for assembly of clamps for clamping seal body at a plurality of locations. The position of these clamps is between every consecutive hole [3,13]. The other adjacent holes [4] are for assembly of bolts which acts as support for these clamps.

There is plurality of counter holes [5] with counter diameter for passing of clamping bolts for clamping of fixture [F] on T slot of machine table.

There is plurality of holes [6] on face A or B is for lifting of fixture or fixture with job through eye bolts with help of overhead EOT crane and other set of at least two holes [6] on side face of fixture [F] is for over turning of fixture through eye bolts i.e. for switching from one face say [A] to face [B] and vice versa.

From the above, working of invention can be understood particularly by a person skilled in the art.
ADVANTAGES OF INVENTION:
- Only cross verification of straightness of joint face of seal body is required by operator which saves a lot of cost expensive man-hours and reduces the operator dexterity required in aligning the job with respect to the machine tool;

- Using the said fixture [F] as discussed herein, the seal body [W] can be rigidly clamped and can be manufactured while eliminating the issues in the prior art;

- User friendly;

- Works efficiently.

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.

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.

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”.

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.

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.

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.

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. Fixture for machining seal body of a large size turbo generator constitutes a semicircular piece having two faces [A, B], each of which comprising of a slot [1] and a stopper collar [2], in which the collar [2] fits into T-slot of a standard machine table and automatically aligns the joint face of the seal body [W], a plurality of holes [3] in the fixture [F] at a common PCD of the seal body [W], multitude of holes [4] provided for assembly of clamps for clamping seal body [W] at a plurality of locations, counter holes [5] with counter diameter for passing of clamping bolts for clamping of the fixture [F] on T slot of machine table and multiple holes [6] for lifting of the fixture [F].

2. The Fixture for machining seal body of a large size turbo generator as claimed in claim 1, comprises of a face ‘A’ provided for machining of seal body of large rating generator sets of the likes of 660 to 800 MW and another face ‘B’ designed for machining of seal body of 500 and 600 MW turbo generator, in which both the faces ‘A and B’ are identical except the slot 1 for which depth is different for both the faces A and B.

3. The Fixture for machining seal body of a large size turbo generator as claimed in claim 1 or 2, wherein the seal body [W], extruded collar [11] of which snugly fits into the slot [1] of the fixture [F], which provides support to the seal body [W] while allowing the rotary degree of freedom to the work piece seal body [W] while remaining in the slot [1] and this helps in rotating the job [W] in the slot [1] of the fixture [F], if required.

4. The Fixture for machining seal body of a large size turbo generator as claimed in claims 1-3, wherein the stopper collar [2] serves functions including One, it gets fit into T-slot of a standard machine table as it is extruded and two, automatically aligns the joint face of seal body when the joint face [12] of seal body [W] touches the said stopper collar [2] thereby eliminating the need for dialing and truing the joint face [12] of seal body [W].

5. The Fixture for machining seal body of a large size turbo generator as claimed in claims 1-4, wherein while using one face [A] of fixture [F] for holding seal body [W], the stopper collar [2] in face [B] gets fitted into [T] slot of machine table and the stopper collar [2] of face [A] automatically aligns the joint face of seal body, and while using other face [B] of the fixture [F] for holding seal body, the stopper collar [2] in face [A] gets fitted into T slot of machine table and the stopper collar [2] of face [B] automatically aligns the joint face of the seal body.

6. The Fixture for machining seal body of a large size turbo generator as claimed in claims 1-5, wherein the holes [3] save the fixture from getting damaged while drilling holes at same PCD in seal body and the fixture holes [3] axis aligned with the axis of the job [W] which in turn is aligned with the axis of the drill bit.

7. The Fixture for machining seal body of a large size turbo generator as claimed in claims 1-6, wherein the plurality of holes [4] are provided on the fixture [F] wherein the necessary clamps are equipped to hold the job [W], in which the position of the clamps is between every consecutive hole [3,13] and the other adjacent holes [4] are for assembly of bolts which act as support for the clamps.

8. The Fixture for machining seal body of a large size turbo generator as claimed in claims 1-7, wherein the holes [6] on face [A, B] are provided for lifting of fixture, alternatively the fixture with job through eye bolts with the help of overhead EOT crane and other set of at least two holes [6] on side face of the fixture [F] is for over turning of fixture through eye bolts i.e. for switching from one face [A] to another face [B] and vice versa.