FIELD OF INVENTION
[001] The present invention disclosure generally relates to the design and development of mechanized building bars with variable thickness. More particularly the invention relates to a device which has been developed to reduce shifting of the stampings and to reduce error alignment of the stampings.
BACKGROUND OF THE INVENTION
[002] The stator is the stationary part of a rotary dynamoelectric systems such as electric generators, electric motors, sirens or mud motors etc. In an electric motor, the stator provides a rotating magnetic field that drives the rotating armature; while in a generator, the stator converts the rotating magnetic field to electric current. Thus, depending on the configuration of a spinning electromotive device the stator may act as the field magnet, interacting with the armature to create motion, or it may act as the armature, receiving its influence from moving field coils on the rotor.
[003] A stator, particularly those of large sizes such as the one used in power plants, consists of an outer steel frame housing enclosing a hollow cylindrical core (made up of laminations of silicon steel). The laminations are to reduce hysteresis and eddy current losses.
[004] To build up a stator core, these laminations (stampings) are stacked together to form a cylindrical core. A number of several lacs of stampings of thin sheet are stacked together to form the stator core. Once stacking get completed core press ring is kept on it and with the help of tension bolts laminated-core gets tightened. Core bars are assembled in the slot given at outer diameter of core which requires great degree of accuracy.

[005] Bakelite building bars are used for stacking of core stampings of stator, due to wear and tear thickness of these building bars get reduced resulting the shifting of stampings on either side or introduction of errors in alignment of stampings.
[006] A small shifting of stampings causes misalignment of core stampings resulting difficulty in insertion of tension bolt as well as core bars into their respective slots/holes. Few prior arts which discuss about method for stamping stator core are listed below.
[007] US3842493A titled “Method of manufacturing a stator core for rotary electric machines” discuss about a stator core for rotary electric machines, which is formed by helically and closely winding a steel strip formed by stamping with equally spaced inner slots defining a plurality of equally spaced tooth portions. The steel strip is also formed with notches each on each side of the stem portion of each tooth portion for the purpose of minimizing the plastic deformation stresses induced at the time of winding it.
[008] US4993290A titled “Method of stamping rotor and stator laminations” discuss about a rotor assembly for an electric motor includes a plurality of laminations disposed in a stack, a tension rod extending axially through the rotor lamination stack, and end clamps disposed at each end of the rotor lamination stack and secured to the tension rod for compressing the stack to hold the laminations of the stack fixedly in position by compression. A method of stamping rotor and stator laminations for a doubly salient electric motor from a single piece of metal includes the steps of stamping a rotor lamination out of the piece of metal, and stamping the stator lamination out of the piece of metal offset from the stamping of the rotor lamination so that a tooth of the rotor lamination stamping is taken from the gap between two teeth of the stator lamination stamping. The centroids of the rotor and stator laminations in their stamped locations in the piece of metal are offset from one another.

[009] US20030197443A1 titled “Stator core and method of making” discusses a stator core and method of making, the stator core and a plurality of separate poles are formed from lamination segments that are each stamped from a single piece of stock. The core includes a plurality of fixed pole segments and a plurality of engagement openings configured to receive and engage the separate pole segments. The method of making the stator core allows for maximum use of the material from which the laminations of the stator are stamped as well as an efficient use of the available space within the stator core. In addition, the method allows for maximum copper slot fill.
[0010] None of the three prior art cited herein above discusses the issues related to improper stacking and resulting issues of core ovality and spirality because of erroneous mechanized building bars used for manufacturing core.
[0011] The present invention is directed to overcoming one or more problems set forth above and/or other problems associated with known devices for stamping stator core assemblies.
OBJECTS OF THE INVENTION
[0012] It is therefore a principal object of the present invention is to provide a device for obtaining improved assembly and alignment of stator core.
[0013] Another object of the present invention is to develop the mechanized building bar with locking-unlocking mechanism to ensure the required thickness for stacking of core stampings of stator.
[0014] Another object of the present invention is to develop the mechanized building bars which are easy to handle, user friendly, accurate, easy to assemble and dismantle.

[0015] Another object of the present invention is to develop the mechanized building bars which is used in different size slots and versatile in nature.
[0016] These and other objects and advantages of the present subject matter will be apparent to a person skilled in the art after consideration of the following detailed description taken into consideration with accompanying drawings in which preferred embodiments of the present subject matter are illustrated.
SUMMARY OF THE INVENTION
[0017] This summary is provided to introduce concepts related to a device for obtaining improved assembly and alignment of stator core.
[0018] The present disclosure relates to the device for obtaining improved assembly and alignment of stator core which comprises of a two wedge shaped planks obtained by diagonal cut along the thickness of a scraped building bar. The wedge shaped planks are configured such that one is mirror image of another and assembled together to slide against each other. A tie rod passing through a center hole along longitudinal length of the wedge shaped planks to control the longitudinal movement of the wedge shaped planks.
[0019] In an aspect a washer and a nut mounted on the threaded side of the tie rod for thickness adjustment. A split pin inserted in a pin hole to avoid dismantling of the nut and the washer from its position.
[0020] In an aspect, a locking ring aligned with an eye of the tie rod. The pin hole of the locking ring and the eye of the tie rod coincide with each other and a pin is inserted and caulked with the locking ring to configure as a hinge joint.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0021] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0022] FIG. 1 is a perspective view of stator core stacked with several stampings assembled using guide columns and building bars in an embodiment of the present invention;
[0023] FIG. 2 is enlarged view of the stator core stacked with several stampings assembled with the guide columns and building bars in an embodiment of the present invention;
[0024] FIG. 3 is a perspective view of a mechanized building bar in an embodiment of the present invention;
[0025] FIG. 4 is an isometric view of the mechanized building bar in an embodiment of the present invention;

[0026] FIG. 5 is an isometric view of the mechanized building bar depicting top arrangement in an embodiment of the present invention;
[0027] FIG. 6 is an isometric view of the mechanized building bar depicting bottom arrangement in an embodiment of the present invention;
[0028] FIG. 7 is a front view of the mechanized building bar in an embodiment of the present invention;
[0029] FIG. 8 is an enlarged top view of the mechanized building bar in an embodiment of the present invention;
[0030] FIG. 9 is an enlarged bottom view of the mechanized building bar in an embodiment of the present invention;
[0031] FIG. 10 is a left side view of the mechanized building bar in an embodiment of the present invention;
[0032] FIG. 11 is a right side view of the mechanized building bar in an embodiment of the present invention;
[0033] FIGS. 12A, 12B are perspective view diagrams of Plank A, Plank B of the mechanized building bar in an embodiment of the present invention;
[0034] FIGS. 13A, 13B, 13C and 13D are perspective view diagrams of a tie rod, a washer, a nut and a locking ring of the mechanized building bar in an embodiment of the present invention; and

[0035] FIGS. 14A, 14B, 14C and 14D are perspective view diagrams of a lever, a pin, a round square pin and a split pin of the mechanized building bar in an embodiment of the present invention.
[0036] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS
[0037] 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.
[0038] The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.

[0039] The present invention relates to a design and development of mechanized building bar with variable thickness for guiding the stampings of stator core and other similar assemblies.
[0040] FIG. 1 is a perspective view of stator core (4) stacked with several stampings (3) assembled using guide columns (1) and building bars (2) in an embodiment of the present invention. In a preferred embodiment the stator core (4) of small-size rotary electric machines are usually manufactured by stamping a plurality of ring-like thin materials individually produced from a steel plate through press stamping. The stamping process produces waste material. The waste material is effectively utilized, for instance, for developing mechanized building bar with variable thickness from the scrap. The mechanized building bar is with locking-unlocking mechanism to ensure the required thickness for stacking of core stampings (3) of the stator.
[0041] FIG. 2 is enlarged view of the stator core (4) stacked with several stampings (3) assembled with the guide columns (1) and the building bars (2) in an embodiment of the present invention. In a preferred embodiment for stamping the stator core (4), a plurality of the building bars (2) are formed from a single piece of stock. An example of stock material is steel, powder metal and equivalents thereof. Thus, and in accordance plurality of steel pieces are stamped to form core pieces. The stampings (3) of the stator core (4) includes inner and outer diameters to enhance accurate alignment of the stacked stator core (4). All of the core pieces would be interlocked together as they are stamped to produce the desired core thickness.
[0042] FIG. 3 is a perspective view of a mechanized building bar in an embodiment of the present invention. As shown in FIG.3 the device (100) consists of a two wedge shaped planks (5, 7) which is produced from a scraped building bar. The wedge shaped planks (5, 7) obtained by diagonal cut along the thickness of the scraped building bar.

The wedge shaped planks (5, 7) are positioned such that one is mirror image of another. The wedge shaped planks (5, 7) are finished and assembled again together to slide against each other. The diagonal cutting of the wedge shaped planks (5, 7) generates new faces to coincide against each other. The device (100) comprises various components which are shown in FIGS. 12A, 12B, 13A, 13B, 13C, 13D, 14A, 14B, 14C and 14D respectively.
[0043] FIG. 4 is an isometric view of the mechanized building bar in an embodiment of the present invention. In a preferred embodiment as shown in FIG.3 after the wedge shaped planks (5, 7) coincide on each other, a center hole along the length of the wedge shaped planks (5, 7) is created. A tie rod (6) passing through the center hole along longitudinal length of the wedge shaped planks (5, 7) to control the longitudinal movement of the wedge shaped planks (5, 7). A washer (8) and a nut (9) is mounted on the threaded side of the tie rod (6) for thickness adjustment. After positioning the nut (9), a split pin (14) is inserted in the pin hole to avoid dismantling of the nut (9) and the washer (8) from its position.
[0044] FIG. 5 is an isometric view of the mechanized building bar depicting top arrangement in an embodiment of the present invention. In a preferred embodiment as shown in FIG.3 a locking ring (10) aligned with an eye of the tie rod (6). A pin hole of the locking ring (10) and the eye of the tie rod (6) coincide with each other and a pin (12) is inserted and caulked with the locking ring (10) to configure as a hinge joint.
[0045] FIG. 6 is an isometric view of the mechanized building bar depicting bottom arrangement in an embodiment of the present invention. In one embodiment as shown in FIG. 3, a lever (11) positioned in slot of the locking ring (10) with a round square pin (13) key being inserted and caulked with the locking ring (10) tightly to prevent rotation of the round square pin (13). Using the lever (11) and the round-square pin (13) key, along with other components assembling of the device (100) is completed.

[0046] FIG. 7 is a front view of the mechanized building bar in an embodiment of the present invention. In a preferred embodiment as shown in FIG.3, rotate the lever (11) in clockwise direction. The key slot of the lever (11) is placed on square position of the round-square pin (13) key through which the tie rod (6) comes out from the center hole against the wedge shaped plank (7) with the locking ring (10). When hinge position of the tie-rod (6) is positioned diametrically opposite from the contact face of the locking ring (10), the wedge shaped plank (7) automatically gets locked. After locking, the lever (11) is moved at round portion of the round-square pin/ (Rnd-Sq) (13) and hangs freely due to gravity. For unlocking, the lever (11) is again moved to the square position of the round-square pin (13) key and rotated in counter clockwise direction. In an exemplary embodiment in order to adjust the thickness of the mechanized building bar, the nut (9) is either tightened or loosened to the required calibration using a Vernier caliper.
[0047] FIG. 8 is an enlarged top view of the mechanized building bar in an embodiment of the present invention. In one embodiment, the building bars (2) are constructed from two-pieces, which are snap fitted together wherein the joint is at the mid-core stack thickness. In a preferred embodiment the stator core (4) selected have rectangular slot alignment requirement. In a preferred embodiment the material of the stator core (4) is made up of steel and the steel sheets are stamped out alongside in a width direction.
[0048] FIG. 9 is an enlarged bottom view of the mechanized building bar in an embodiment of the present invention. In one embodiment the building bars (2) are bakelite building bars which are used for stacking of core stampings (3) of the stator. Wear and tear thickness of the building bars (2) are reduced by using the device (100). Using the device (100) shifting of the stampings (3) and alignment errors of the stampings (3) are reduced. The device (100) material being used are made from

scraped building bars. The stamping of the stator core (4) reduces the deformation of the stator core (4) at the time of stator winding.
[0049] FIG. 10 is a left side view of the mechanized building bar & FIG. 11 is a right side view of the mechanized building bar in an embodiment of the present invention. In a preferred embodiment in the forming of such mechanized building bar, the thickness of the stampings (3) is measured. The building bars (2) with locking-unlocking mechanism ensure the required thickness for stacking of core stampings (3) of the stator. In a preferred embodiment the stator core (4) is selected from a group of electric generators, electric motors, sirens, mud motors and other similar assemblies.
[0050] FIGS. 12A, 12B are perspective view diagrams of the Plank A (5), Plank B (7) of the mechanized building bar in an embodiment of the present invention.
[0051] FIGS. 13A, 13B, 13C and 13D are perspective view diagrams of the tie rod (6), the washer (8), the nut (9) and the locking ring (10) of the mechanized building bar in an embodiment of the present invention.
[0052] FIGS. 14A, 14B, 14C and 14D are perspective view diagrams of the lever (11), the pin (12), the round square pin (13) and the split pin (14) of the mechanized building bar in an embodiment of the present invention. Various components of the mechanized building bar are used for stacking of core stampings of stator and prevent wear & tear thickness such that errors in alignment of stampings is reduced.
[0053] In one embodiment the mechanized building bars are easy to handle, user friendly, accurate, easy to assemble and dismantle. The mechanized building bars are used in different size slots which makes the device (100) versatile.

[0054] 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 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. 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. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0055] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope. The present invention will now be described more specifically with reference to the following specification.
[0056] 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 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. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0057] Although embodiments for the present subject matter have been described in language specific to package features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/device of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.
[0058] 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 particular 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 analogous 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.”

[0059] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited feature.
[0060] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

WE CLAIM:
1. A device (100) for obtaining improved assembly and alignment of stator core (4), the device (100) comprising:
- a two wedge shaped planks (5,7) obtained by diagonal cut along the thickness of a scraped building bar, wherein said wedge shaped planks (5,7) are configured such that one is mirror image of another and assembled again together to slide against each other;
- a tie rod (6) passing through a center hole along longitudinal length of said wedge shaped planks (5,7) to control the longitudinal movement of the wedge shaped planks (5,7);
- a washer (8) and a nut (9) mounted on the threaded side of the tie rod (6) for thickness adjustment;
- a split pin (14) inserted in a pin hole to avoid dismantling of the nut (9) and the washer (8) from its position;
- a locking ring (10) aligned with an eye of the tie rod (6) , wherein the pin hole of the locking ring (10) and the eye of the tie rod (6) coincide with each other and a pin (12) is inserted and caulked with the locking ring (10) to configure as a hinge joint;
- a lever (11) positioned in slot of the locking ring (10) with a round square pin (13) key being inserted and caulked with the locking ring (10) to prevent rotation of the round square pin (13), and wherein said lever (11) along with the round square pin (13) key rotated in clockwise and counter clockwise direction for locking & unlocking respectively with the nut (9) being adjusted to vary thickness of the device (100).

2. The device (100) as claimed in claim 1, wherein the stator core (4) selected have rectangular slot alignment requirement.
3. The device (100) as claimed in claim 1, wherein the stampings (3) of the stator core (4) includes inner and outer diameters to enhance accurate alignment of the stacked stator core (4).
4. The device (100) as claimed in claim 1, wherein the stampings (3) of the stator core (4) reduces the deformation of the stator core (4) at the time of stator winding.
5. The device (100) as claimed in claim 1, wherein the diagonal cutting of said wedge shaped planks (5, 7) generates new faces to coincide against each other.