Claims:We claim:
1. An apparatus (D) for manufacturing of slot tightening and ventilation component of a stationary or rotating member of a dynamoelectric machine, the apparatus (D) comprising:
a base plate (100) having a top face and a bottom face, wherein the base plate (100), on the top face, is provisioned with longitudinally extending milled grooves (200, 300, 400) for holding slot wedge median part (T) and a keybar (P) in a direction longitudinal to a cutter movement;
a plurality of corner holes (240) formed on non-milled corners of the top face of the base plate (100), wherein a threaded hole (230) is formed next to each of the plurality of corner holes (240) to adjust the base plate (100) against irregularities of a machine table;
a locking unit (600) formed on the bottom face of the base plate (100) to lock rotational degree of freedom of base plate (100) against the machine table;
a plurality of clamp units (500) disposed on top face of the base plate (100), wherein the plurality of clamp units (500) with their peripheral through holes (510) are threadedly locked with corresponding threaded holes (550) in the base plate (100) so as to lock the median part (T) in a first groove (200) of the longitudinally extending milled grooves (200, 300, 400);
an end support (210) formed at one end of the first groove (200) to lock further forward movement of the median part (T) in the first groove (200);
cutter paths (220) formed in the first groove (200) of the base plate (100) in such a manner that the cutter paths (220) accommodate maximum drilling depth, attained by standard drilling means, in the base plate (100);
a plurality of threaded holes (420) formed on lateral walls of second and third grooves (300, 400) of the longitudinally extending milled grooves (200, 300, 400) to rigidly hold the keybar (P, R) in the second and third grooves (300, 400) of the base plate (100);
a plurality of grooves (410) formed on the lateral walls of the third groove (400) of the base plate (100) to provide provision for deployment of quality check instruments; and
a plurality of threaded holes (700) formed, in the region of locking unit (600), on the front face of the base plate (100) so as to lift the apparatus (D) using I-bolts for transportation among different machines.
2. The apparatus (D) as claimed in claim 1, wherein the depth of the first groove (200) is lesser than the slot wedge median part (T) so that a partial slot wedge median part (T), from its top surface, is upwardly protruding out in relation to the base plate (100).
3. The apparatus (D) as claimed in claim 1, wherein the width of the first groove (200) is equal to the width (W) of the slot wedge median part (T) added with small tolerance so that the slot wedge median part (T) is longitudinally inserted in the first groove (200).
4. The apparatus (D) as claimed in claim 1, wherein the depth of the second groove (300) is selected in such a way that the second groove (300) ensures to accommodate the keybar (P) in a way that partial keybar (P), from its top surface (KB1), is upwardly protruding out in relation to adjacent surfaces of the base plate (100).
5. The apparatus (D) as claimed in claim 1, wherein the width of the second groove (300) is equal to the width (W’) of the keybar (P) added with a small tolerance.
6. The apparatus (D) as claimed in claim 1, wherein the width of the third groove (400) is equal to the height (H’) of the keybar (R) added with a small tolerance.
7. The apparatus (D) as claimed in claim 1, wherein the depth of the third groove (400) is selected in such a way that the third groove (400) ensures to accommodate the keybar (R) in a way that partial keybar (R), from its top surface (KB1), is upwardly protruding out in relation to the adjacent surfaces of the base plate (100).
8. The apparatus (D) as claimed in claim 1, the base plate (100) is made using alloy steel.
9. The apparatus (D) as claimed in claim 1, wherein the stationary member is a stator and the rotating member is a rotor, and wherein the quality check instruments includes a vernier caliper or micrometer for measuring bending and to ensure production quality of the slot tightening and ventilation component.
10. A method of implementing the apparatus (D), as claimed in any of the claims 1-9, for manufacturing of slot tightening and ventilation component of a stationary or rotating member of a dynamoelectric machine, the method comprising:
securing the base plate (100) in T-slots on a flat planar top surface of a standard machine table using the locking unit (600) and by threadedly affixing the plurality of clamping elements using the corner holes (240) and the threaded holes (230) respectively, wherein the clamping elements are T-bolts;
inserting longitudinally an individual slot wedge median part (T) in the first groove (200) such that one distal end of the slot wedge median part (T) butts with the end support (210) to lock its further forward movement in the first groove (200) and such that partial slot wedge median part (T), from its top surface, is upwardly protruding out in relation to the adjacent surface of the base plate (100);
fastening clamp units (500) over and across the slot wedge median part (T) using a plurality of threaded bolts that pass through the holes (510) on in and access corresponding threaded holes (550) formed in the base plate (100) such that the slot wedge median part (T) is rigidly held in the first groove (200) upon tightening by one end of the clamp units (500) while another end of the clamp units (500) is rested on threaded support in secondary threaded holes (560) formed adjacent to the threaded holes (550);
performing machining operations on the top surface of the slot wedge median part (T);
turning the slot wedge median part (T) upside down by unclamping the clamp units (500) and repeating the machining operations on opposite surface of the slot wedge median part (T);
placing the keybar (P) in the second groove (300) and securing the keybar (P) by a threaded connection accessing and passing through the threaded holes (420) formed on the lateral walls of the second groove (300);
performing machining operations on the top surface (KB1) of the keybar (P); and
turning the keybar (P) upside down by unclamping the clamp units (500) and repeating the machining process on opposite surface of the keybar (P).
, Description:APPARATUS AND METHOD FOR MANUFACTURING OF SLOT TIGHTENING AND VENTILATION COMPONENT IN DYNAMOELECTRIC MACHINE
TECHNICAL FIELD
[0001] The present disclosure, in general, relates to a dynamoelectric machine and, in particular, relates to an apparatus and a method for obtaining great accuracy in the manufacturing of slot tightening and ventilation component of a stationary or rotating member, such as a rotor or stator, of the dynamoelectric machine.
BACKGROUND
[0002] 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.
[0003] In large size turbo-generators, rotor windings have recently been cooled by placing a coolant gas in direct contact with a conductor to more effectively dissipate the heat from the windings. In a rotor cooled in this manner, all or part of the windings is cooled by admitting the cooling gas to passages within the main conductor insulation by means of ports located in end turn portions, under retaining rings. Cold gas enters the overhang from under the retaining rings through the special chamber in the end shields and ducts under the fan hub and is further carried through the rotor conductor end windings to an intermediate portion of the rotor, and then exhausts to the air gap through pole face slots.
[0004] These slots are conventionally disposed with a plurality of, longitudinally extending and disposed circumferentially around rotor longitudinal axis, slot closing wedges which hold the slot contents, e.g., coils, slot filler, within the slots. The slot contents should remain tight to prevent relative motion of the copper windings during slow roll operations which could result in wear of the windings and conductive particle creation. Tight slot content also ensures the provision of adequate contact pressure on a damper system of the rotor, e.g., a wedge and rotor tooth, at low speeds to conduct currents generated with static start operation.
[0005] These longitudinally extending slot wedges have a median member with plurality of chamfered ventilation slots to provide a path for conducting heat away from conductors by means of electrically insulated slot wedges including a central metal body of high thermal conductivity used both to hold the conductors in slots and to effect thermal transfer, conduction and dissipation to outside the slots.
[0006] In stator component of the dynamoelectric machine, a plurality of keybars extending outward from a surface of the longitudinal stator, wherein each of the plurality of keybars is disposed axially along and circumferentially around the longitudinal laminated stator core, further wherein an axis of the plurality of keybars is parallel to the longitudinal axis of the stator. These keybar are significant in reducing torque ripple in the stator.
[0007] Over time and during use of the dynamoelectric machine, if these slot tightening means such as slot wedge and keybar are not machined with precise dimensional accuracy, rotor or stator coils may become loose which can cause catastrophic failure in an electric generator. Such looseness is obviously undesirable and it is required that these slot wedges and keybar are accurately manufactured without fault or err. The present method and means of manufacturing these slot wedges as well as keybar are designed to prevent axial displacement of shifting of the wedges in the slots and to eliminate the possibility of the wedges or keybar slipping out of the slots during operation of the machine, as a result of electrical and mechanical forces.
[0008] The conventional methods perform different operations on slot wedges as well as keybar on a plurality of manufacturing machines, which not only resulted in expensive time delays in multiple jobs and related tool settings but also in transferring the said slot tightening means on a different machine. Also, all these machines are required to be sequentially lined up to accommodate, without delay, these slot tightening means in their manufacturing schedule. Multiple job settings not only created operator fatigue but also reduced the job quality for obvious reasons well known to the person skilled in the art.
OBJECTS OF THE DISCLOSURE
[0009] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed hereinbelow.
[0010] It is a general object of the present disclosure to provide an apparatus and an associated method for machining slot tightening means, such as slot wedge and keybar while eliminating issues related to prior art such as poor manufacturing quality and low production efficiency.
[0011] It is an object of the present disclosure to provide an apparatus and an associated method for machining slot tightening means, such as slot wedge and keybar, which provide enhanced ergonomics and reduced operator fatigue.
[0012] It is another object of the of present disclosure to provide an apparatus and an associated method for machining slot tightening means, such as slot wedge and keybar, which makes it possible that a number of operations are performed on single means to significantly reduce setting/machining time and expensive delays in machining of slot tightening means on different machining.
[0013] It is yet another object of the present disclosure to provide an apparatus and an associated method for machining slot tightening means, such as slot wedge and keybar, of the above character wherein the said means have minimum number of structurally durable parts cooperatively assembled in a compact organization and the said method is simple, economical, foolproof and inherently free from tendency to error or fall out of adjustment
SUMMARY
[0014] This summary is provided to introduce concepts related to an apparatus and a method for obtaining great accuracy in the manufacturing of slot tightening and ventilation component of a stationary or rotating member, such as a rotor or stator, of the dynamoelectric machine. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0015] In an embodiment, the present disclosure relates to an apparatus for manufacturing of slot tightening and ventilation component of a stationary or rotating member of a dynamoelectric machine. The apparatus includes a base plate having a top face and a bottom face, wherein the base plate, on the top face, is provisioned with longitudinally extending milled grooves for holding slot wedge median part and a keybar in a direction longitudinal to a cutter movement. Further, the apparatus includes a plurality of corner holes formed on non-milled corners of the top face of the base plate, wherein a threaded hole is formed next to each of the plurality of corner holes to adjust the base plate against irregularities of a machine table. Also, the apparatus includes a locking unit formed on the bottom face of the base plate to lock rotational degree of freedom of base plate against the machine table; a plurality of clamp units disposed on top face of the base plate, wherein the plurality of clamp units with their peripheral through holes are threadedly locked with corresponding threaded holes in the base plate so as to lock the median part in a first groove of the longitudinally extending milled grooves; an end support formed at one end of the first groove to lock further forward movement of the median part in the first groove; cutter paths formed in the first goove of the base plate in such a manner that the cutter paths accommodate maximum drilling depth, attained by standard drilling means, in the base plate; a plurality of threaded holes formed on lateral walls of second and third grooves of the longitudinally extending milled grooves to rigidly hold the keybar in the second and third grooves of the base plate; a plurality of grooves formed on the lateral walls of the third groove of the base plate to provide provision for deployment of quality check instruments; and a plurality of threaded holes formed, in the region of locking unit, on the front face of the base plate so as to lift the appartus using I-bolts for transportation among different machines.
[0016] In an aspect, the depth of the first groove is lesser than the slot wedge median part so that a partial slot wedge median part, from its top surface, is upwardly protruding out in relation to the base plate.
[0017] In an aspect, the width of the first groove is equal to the width of the slot wedge median part added with small tolerance so that the slot wedge median part is longitudinally inserted in the first groove.
[0018] In an aspect, the depth of the second groove is selected in such a way that the second groove ensures to accommodate the keybar in a way that partial keybar, from its top surface, is upwardly protruding out in relation to adjacent surfaces of the base plate.
[0019] In an aspect, the width of the second groove is equal to the width of the keybar added with a small tolerance.
[0020] In an aspect, the width of the third groove is equal to the height of the keybar added with a small tolerance.
[0021] In an aspect, the depth of the third groove is selected in such a way that the third groove ensures to accommodate the keybar in a way that partial keybar, from its top surface, is upwardly protruding out in relation to the adjacent surfaces of the base plate.
[0022] In an aspect, the base plate is made using alloy steel.
[0023] In an aspect, the stationary member is a stator and the rotating member is a rotor. Also, the quality check instruments include a vernier caliper or micrometer for measuring bending and to ensure production quality of the slot tightening and ventilation component.
[0024] In an embodiment, the present disclosure further relates to a method of implementing the proposed apparatus for manufacturing of slot tightening and ventilation component of a stationary or rotating member of a dynamoelectric machine. The method includes securing the base plate in T-slots on a flat planar top surface of a standard machine table using the locking unit and by threadedly affixing the plurality of clamping elements using the corner holes and the threaded holes respectively, wherein the clamping elements are T-bolts; inserting longitudinally an individual slot wedge median part in the first groove such that one distal end of the slot wedge median part butts with the end support to lock its further forward movement in the firt groove and such that partial slot wedge median part, from its top surface, is upwardly protruding out in relation to the adjacent surface of the base plate; fastening clamp units over and across the slot wedge median part using a plurality of threaded bolts that pass through the holes on in and access corresponding threaded holes formed in the base plate such that the slot wedge median part is rigidly held in the first groove upon tightening by one end of the clamp units while another end of the clamp units is rested on threaded support in secondary threaded holes formed adjacent to the treaded holes; performing machining operations on top surface of the slot wedge median part; turning the slot wedge median part upside down by unclamping the clamp units and repeating the machining operations on opposite surface of the slot wedge median part; placing the keybar in the second groove and securing the keybar by a threaded connection accessing and passing through the threaded holes formed on the lateral walls of the second groove; performing machining operations on the top surface of the keybar; and turning the keybar upside down by unclamping the clamp units and repeating the machining process on opposite surface of the keybar.
[0025] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] 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 apparatuses, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
[0027] FIGS. 1 and 2 illustrate a line representation of the slot containing conductors which are connected at their ends to form the rotor winding;
[0028] FIGS. 3 and 4 illustrate a line representation of the laying structure of individual turns of a winding in rotor slot, ventilation duct, and its insulation in accordance with an exemplary embodiment of the present disclosure;
[0029] FIG. 5 illustrates a line representation of the ventilation circuit in a turbo-generator rotor in accordance with an embodiment of the present disclosure;
[0030] FIG. 6 illustrates a line representation of the top view of the proposed apparatus in accordance with an embodiment of the present disclosure;
[0031] FIG. 7 illustrates a line representation of side view of one working method of proposed apparatus in accordance with an embodiment of the present disclosure;
[0032] FIG. 8 illustrates an illustrative view of the proposed apparatus in accordance with an embodiment of the present disclosure;
[0033] FIG. 9 illustrates an illustrative view of slot tightening and ventilation component in the proposed apparatus in accordance with an embodiment of the present disclosure;
[0034] FIG. 10 illustrates an illustrative view of the slot ventilation component in accordance with an embodiment of the present disclosure;
[0035] FIG. 11 illustrates an illustrative view of a slot tightening component in accordance with an embodiment of the present disclosure; and
[0036] FIGS. 12A and 12B illustrate a method of implementing the proposed apparatus, in accordance with an embodiment of the present disclosure;
DETAILED DESCRIPTION
[0037] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0038] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0039] Further, before describing the present subject matter in detail the method and apparatus for accurate manufacturing slot tightening means, such as slot wedges and keybar and mechanism, it should be observed that the present invention resides primarily in a novel and non-obvious combination of hardware elements and method steps.
[0040] Referring now to FIGS. 1 and 2 in detail, which illustrates a general construction of an alternating current (AC) generator rotor, the field windings are embedded and wedged into rotor slots 11 in a peripheral surface 12 of a rotor 10. The rotor slots 11 cover only part of the peripheral surface 12 and are disposed on either side of poles 13, the whole field winding forming a spiral around each pole center. The peripheral/outer surface 12 of the rotor 10 is generally divided, in the circumferential direction, between winding regions 11 and pole regions 13. Each winding region is provided with a plurality of axially extending slots 11, separated by teeth 15, where the slots 11 containing conductors which are connected at their ends to form the rotor winding.
[0041] Referring now to FIGS. 3 and 4 in detail, the rectangular cross-section copper conductors 25 have annular ventilating ducts 21, and thus providing a longitudinal channel 22 for hydrogen flow in rotor 10 (shown in FIG. 5). Further, a plurality of individual conductors 25 placed, one over the other, in the slot 11 on rotor’s peripheral surface 12 and are bent to obtain half turns. Further, these half turns are brazed in series to form a coil on the rotor model. Dovetailed shaped wedges 23 having intermittent openings 31, along with the top of the slot 11 over the entire length of outer conductor 25, secure the windings 20 against centrifugal forces arising due to rotation of the rotor 10. The winding is shown in more details in FIG. 5.
[0042] The individual turns 24 in a winding 20 are insulated from each other by a layer of glass strips 26 on the turn of copper and baked under pressure and temperature to give a monolithic inter-turn insulation. The coils 24 are insulated from rotor body 10 by U-shaped glass laminate 27. At the bottom of slot D-shaped liners 28 are put to provide a plane seating surfaces for conductors 25 and to facilitate easy flow of gas from one side to another.
[0043] To guide the cold gas towards the center of the rotor so as to exhaust the same to the air gap 29, the slot wedge 23 above the conductor 25 consists of a plurality of openings 31 as per ventilation design is shown in FIG. 5, and fillers 30 are caulked in the slot recess 32 to restrict and redirect the gas flow towards the said air gap 29 through a plurality of gas flow channels 29’.
[0044] However, power plant turbo generators operate at 3000 rpm and under high centrifugal forces thereof, if these slot tightening means such as slot wedge and keybar are not machined with precise dimensional accuracy, slot wedge tightening means may become loose. If a rotor slot wedge or key bar becomes loose, it can permit a rotor coil to vibrate, which can cause catastrophic failure in an electric generator. Such looseness is obviously undesirable and it is required that these slot wedges and keybar are accurately manufactured without fault or err.
[0045] To this end, the present subject matter proposes an apparatus D as shown in FIGS. 6-9 comprising of a base plate 100 that primarily affixes with the standard machine table in a horizontal plane parallel to that of the machine table and perpendicular to the vertical axis to hold slot tightening means.
[0046] As shown in FIGS. 6 and 7, parallelepipedic base plate 100, made using alloy steel and having parallel top and bottom faces and locking unit 600 on its bottom face. While extruded locking unit 600 longitudinally sits in one of the T-slot of the machine table to lock rotational degree of freedom of base plate 100, plurality of holes 240 rectangularly arrayed and disposed on corners of base plate 100 are used by plurality of clamping elements, generally T-bolts and corresponding nut, for threadedly securing base plate 100 to the flat planar top surface of said, not shown in figures, standard machine table. Because the shoulders of such T-bolts are made carefully plane, the T-bolts will project at right angles with respect to the base plate 100 axes to keep in a horizontal plane and is known to someone skilled in the art.
[0047] For instances where the machine bed is not truly in a horizontally plane, plurality of threaded holes 230, disposed on the base plate 100 and configured next to each hole 240, receive threaded means such as a standard grub screw which threadedly pass through corresponding hole 230 in varying lengths to ensure that base plate 100 is in a horizontal plane before securing the said base plate to machine bed or table through hole 240. In a similar manner, the said grub screws can also be used to secure the said base plate 100 in an angular plane, if required.
[0048] Further, the said base plate 100 is provisioned, on its top face, with longitudinally extending milled grooves 200, 300 and 400 for holding slot wedge median part and keybar in a direction longitudinal to the cutter movement.
[0049] The depth of grooves 200 is selected in such a way that it ensures to accommodate the slot wedge median part T in a way that partial slot wedge, from its top surface, is upwardly protruding out in relation to adjacent surface, as shown in figure 7 and 8, to facilitate critical machining operations median parts such as drilling and chamfering of ventilation holes.
[0050] As shown in FIGS. 7 and 9, once the base plate is secured in the machine table, slot wedge median part T is slidably inserted in groove 200 such that one distal end face of the slot wedge median part butts with end support 210 to lock its further forward movement in the groove 200. It is advisable that actual grooves 200 size is as per slot wedge median part T width W added very close tolerances so that when the individual median part is longitudinally inserted in grooves 200, said groove prevents the median part from rattling or from vibrations during the drilling process.
[0051] After inserting the median part in groove 200 as mentioned hereinabove, a plurality of clamp units 500 are threadedly used to lock median part T in its recessed location 200. The said clamp units 500, initially at a position 540, are fastened in a horizontal plane at a position 520 through position 530 over and across median part as shown in FIG. 7 such that one end of clamp units 500 partially overlaps and rests over protruding height H of the median part while the other end of said clamp units 500 rests on a grub screw threadedly disposed to similar height H in corresponding threaded hole 530. A power screw such as a plurality of threaded bolt passes through holes 510 on clamp unit 500 and access corresponding threaded holes 550 in base plate 100 such that tightening of said power screws adequately compresses median part T to additionally secure, along with groove 200 sides and end support 210, the sais median part from rattling or from vibrations while it is subjected to various machining forces. It being imperative that the congruent surfaces between median part T and groove 200 be free and clear of debris such as chips or cuttings.
[0052] Once all the ventilation holes 570 on one half of slot wedge T, shown along A axis in FIG. 10, are accurately drilled and chamfered, clamp units 500 on one side of slot wedge part are unfastened to a position 540 and laterally opposite clamp units 500 one other side is fastened in a horizontal plane over and across a median part in a similar manner to repeat machining operation across B axis.
[0053] To ensure that drilling means BIT does not hit base plate 100, it is imperative that depth of cutter paths 220 in such a way that that accommodates the maximum drilling means depth in the base plate.
[0054] The same apparatus D also consists of independent means 300, 400 for machining of keybar, which is again a slender parallelepipedic body, in which keybar is first placed in groove 300 for surface preparation through a milling cutter Saw-1 as shown in figure 7 and figure 9. The keybar P, as shown in figure 11, is first placed in groove 300 and is secured in its position from its lateral sides KB2 by a threaded connection such as a grub screw accessing and passing through threaded hole 420 and compressing keybar P through its lateral face surface KB2 against groove 300 surface upon tightening. Surface milling or any other surface preparation operation are now worked upon keybar top surface KB1. Upon this, the keybar is turned upside down and the process is repeated to fully prepare both the sides.
[0055] As shown in FIGS. 7 and 9, the depth of grooves 300 is selected in such a way that it ensures to accommodate the keybar P in a way that partial keybar, from its top surface, is upwardly protruding out in relation to adjacent surfaces of the base plate 100. This facilitates uninterrupted machining operations on keybar such as surface milling. Also, it is imperative that actual grooves 300 width is as per keybar P width W’, shown in FIG. 7, added very close tolerances so that when individual keybar is longitudinally inserted and locked in grooves 300, said groove prevents the median part from rattling or from vibrations during the drilling process.
[0056] The operation is repeated for preparation of keybar width face surface KB2 using a Cutter Saw-2. This is accomplished by placing keybar in groove 400 and is secured in its position from sides KB1 by a threaded connection such as a grub screw accessing and passing through threaded hole 420 and compressing keybar P, through its lateral face surface KB1 against groove 300 surface, upon tightening. Surface milling or any other surface preparation operation are now worked upon keybar surface KB2. Upon this, the keybar is turned upside down and the process is repeated to fully prepare both the sides.
[0057] The depth of grooves 400 is selected in such a way that it ensures to accommodate the keybar in a way that partial keybar, from its top surface KB1, is upwardly protruding out in relation to adjacent surfaces, as shown in FIG. 7, to facilitate critical machining operations on keybar median part such as surface milling. Also, it is imperative that actual grooves 400 width is as per keybar P height H’ added very close tolerances so that when individual keybar is placed and locked in grooves 400, said groove prevents keybar from rattling or from vibrations during the drilling process.
[0058] It being imperative that the congruent surfaces between keybar P and groove 300,400 be free and clear of debris such as chips or cuttings.
[0059] A plurality of grooves 410 on base plate 100 lateral to base plate axis are configured in order to provide an approach for quality check instruments such as a Vernier Calliper or micrometer for measuring bending and to ensure product quality.
[0060] The means as described hereinabove shall be really useful in accurately machining these critical parts as slot wedge is generally made on high thermal conductivity materials which are not only expensive but are highly prone to dimensional inaccuracy and issues such as key bar bending if not held rigidly during machining.
[0061] The present disclosure thus proposes a mechanism to locks and prevents any movement of jobs during machining by rigidly holding the same which greatly enhances the safety of the ventilation component and of the turbogenerator for that matter.
[0062] FIGS. 12A and 12B illustrate a method 1200 implementing the proposed apparatus for manufacturing of slot tightening and ventilation component of a stationary or rotating member of a dynamoelectric machine, in accordance with an embodiment of the present disclosure. The order in which the method 1200 is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method 1200, or an alternative method.
[0063] At block 1202, the method 1200 includes securing the base plate (100) in T-slots on a flat planar top surface of a standard machine table using the locking unit (600) and by threadedly affixing the plurality of clamping elements using the corner holes 240 and the threaded holes (230) respectively. The clamping elements can be T-bolts;
[0064] At block 1204, the method 1200 includes inserting longitudinally an individual slot wedge median part (T) in the first groove (200) such that one distal end of the slot wedge median part (T) butts with the end support (210) to lock its further forward movement in the first groove (200) and such that partial slot wedge median part (T), from its top surface, is upwardly protruding out in relation to the adjacent surface of the base plate (100).
[0065] At block 1206, the method 1200 includes fastening clamp units (500) over and across the slot wedge median part (T) using a plurality of threaded bolts that pass through the holes (510) on in and access corresponding threaded holes (550) formed in the base plate (100) such that the slot wedge median part (T) is rigidly held in the first groove (200) upon tightening by one end of the clamp units (500) while another end of the clamp units (500) is rested on threaded support in secondary threaded holes (560) formed adjacent to the threaded holes (550).
[0066] At block 1208, the method 1200 includes performing machining operations on the top surface of the slot wedge median part (T).
[0067] At block 1210, the method 1200 includes turning the slot wedge median part (T) upside down by unclamping the clamp units (500) and repeating the machining operations on opposite surface of the slot wedge median part (T).
[0068] At block 1212, the method 1200 includes placing the keybar (P) in the second groove (300) and securing the keybar (P) by a threaded connection accessing and passing through the threaded holes (420) formed on the lateral walls of the second groove (300).
[0069] At block 1214, the method 1200 includes performing machining operations on the top surface (KB1) of the keybar (P).
[0070] At block 1216, the method 1200 includes turning the keybar (P) upside down by unclamping the clamp units (500) and repeating the machining process on opposite surface of the keybar (P).
[0071] Further, it is discovered that through the use of a specially designed method as discussed herein through which not only it is desired to have to save significant time and with lesser resources to manufacture such keybars and slot wedges with accuracy but also with the apparatus that makes this achievable with an arrangement having low initial cost and upkeep, great and continuing accuracy inherent in its design and operation, ruggedness and simplicity in its construction and operation, all to the ultimate end of faithfully and consistently reproducing in and through the desired quality of machining of said slot tightening component.
[0072] Thus, the present subject matter proposes a mechanism to lock and prevent any movement of jobs during machining by rigidly holding the same which greatly enhances the safety of the ventilation system and of the turbogenerator for that matter.
[0073] The present subject matter herein describes an apparatus D for manufacturing of slot tightening and ventilation component of a stationary or rotating member of a dynamoelectric machine. The apparatus D comprising a base plate 100 having a top face and a bottom face, wherein the base plate 100, on the top face, is provisioned with longitudinally extending milled grooves 200, 300, 400 for holding slot wedge median part T and a keybar P, R in a direction longitudinal to a cutter movement. Further, the apparatus D includes a plurality of corner holes 240 formed on non-milled corners of the top face of the base plate 100, wherein a threaded hole 230 is formed next to each of the plurality of corner holes 240 to adjust the base plate 100 against irregularities of a machine table. Also, the apparatus D includes a locking unit 600 formed on the bottom face of the base plate 100 to lock rotational degree of freedom of base plate 100 against the machine table; a plurality of clamp units 500 disposed on top face of the base plate 100, wherein the plurality of clamp units 500 with their peripheral through holes 510 are threadedly locked with corresponding threaded holes 550 in the base plate 100 so as to lock the median part T in a first groove 200 of the longitudinally extending milled grooves 200, 300, 400; an end support 210 formed at one end of the first groove 200 to lock further forward movement of the median part T in the first groove 200; cutter paths 220 formed in the first goove 200 of the base plate 100 in such a manner that the cutter paths 220 accommodate maximum drilling depth, attained by standard drilling means, in the base plate 100; a plurality of threaded holes 420 formed on lateral walls of second and third grooves 300, 400 of the longitudinally extending milled grooves 200, 300, 400 to rigidly hold the keybar P, R in the second and third grooves 300, 400 of the base plate 100; a plurality of grooves 410 formed on the lateral walls of the third groove 400 of the base plate 100 to provide provision for deployment of quality check instruments; and a plurality of threaded holes 700 formed, in the region of locking unit 600, on the front face of the base plate 100 so as to lift the appartus D usign I-bolts for transportation among different machines.
[0074] In an aspect, the depth of the first groove 200 is lesser than the slot wedge median part T so that a partial slot wedge median part T, from its top surface, is upwardly protruding out in relation to the base plate 100.
[0075] In an aspect, the width of the first groove 200 is equal to the width W of the slot wedge median part T added with small tolerance so that the slot wedge median part T is longitudinally inserted in the first groove 200.
[0076] In an aspect, the depth of the second groove 300 is selected in such a way that the second groove 300 ensures to accommodate the keybar P in a way that partial keybar P, from its top surface KB1, is upwardly protruding out in relation to adjacent surfaces of the base plate 100.
[0077] In an aspect, the width of the second groove 300 is equal to the width W’ of the keybar P added with a small tolerance.
[0078] In an aspect, the width of the third groove 400 is equal to the height H’ of the keybar R added with a small tolerance.
[0079] In an aspect, the depth of the third groove 400 is selected in such a way that the third groove 400 ensures to accommodate the keybar R in a way that partial keybar R, from its top surface KB1, is upwardly protruding out in relation to the adjacent surfaces of the base plate 100.
[0080] In an aspect, the base plate 100 is made using alloy steel.
[0081] In an aspect, the stationary member is a stator and the rotating member is a rotor. Also, the quality check instruments include a vernier caliper or micrometer for measuring bending and to ensure production quality of the slot tightening and ventilation component.
[0082] Further, it will be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its scope.
[0083] Furthermore, all examples recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the invention 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. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.
[0084] Further, it will be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its scope.
[0085] Furthermore, all examples recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the invention 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. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.
[0086] The above description does not provide specific details of the 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.
[0087] 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.
[0088] 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.
[0089] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.