Patent Application
20170056980
The disclosure relates generally to a fixture for securing a component to be drilled. More particularly, the disclosure relates to a fixture for securing a transition piece that is to be drilled during replacement of a wear pad in the transition piece and method for drilling the same.
Power generation systems, including gas turbines are widely used. A conventional gas turbine system typically includes, inter alia, a compressor, a combustor, a turbine section, and a transition piece for connecting the flow of the combustor to the turbine section. During operation of the turbine, components experience vibrations which may result in structural wear to those components and/or the turbine itself. In the transition piece of the turbine, wear pads or spacers have been employed to prevent components of the transition piece from becoming worn due to vibrations. For example, wear pads are used in the transition piece between the transition piece (TP) forward ring and the impingement sleeve which surrounds the TP forward ring. While these wear pads are generally successful in preventing wear caused by vibration, it is expensive and difficult to maintain and replace them.
Generally, replacing the wear pads between impingement sleeves and TP forward rings requires disassembling the transition piece and the combustor in order to remove the worn wear pads and insert new wear pads. Impingement sleeves have been manufactured such that impingement sleeves include two or more parts to allow for disassembly of the impingement sleeve when replacing wear pads.
A first aspect of the invention provides for a fixture for securing a component to be drilled. The fixture may comprise: a support structure positioning the component thereon; a template substantially surrounding the component configured to locate a position on the component that is to be drilled, the template being positioned on the support structure and having at least one hole therethrough; and a centering device positioned on the support structure configured to center the component within the template.
A second aspect of the invention provides for a fixture for securing a transition piece of a turbomachine to be drilled. The fixture may comprise: a support structure positioning the transition piece thereon; a template substantially surrounding the transition piece configured to locating a position on the component that is to be drilled, the template being positioned on the support structure and having at least one drill bit hole therethrough; and a centering device positioned on the support structure configured to center the component within the template.
A third aspect of the invention provides for a method for drilling a wear pad replacement hole into a transition piece of a turbomachine. The method may comprise: providing the transition piece within a template on a support structure, the template having at least one hole therethrough; centering the transition piece within the template via a centering device; inserting a drill bit through the at least one hole of the template to drill the wear pad replacement hole into the transition piece.
The illustrative aspects of the present disclosure are designed to solve the problems herein described and/or other problems not discussed.
These and other features of this disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings that depict various embodiments of the disclosure, in which:
It is noted that the drawings of the disclosure are not to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In drawings, like numbering represents like elements between the drawings.
As indicated above, the disclosure provides for a fixture for securing a component which is to be drilled. This disclosure will be described with reference to a transition piece of a turbomachine. However, it is to be understood that embodiments of the fixture as described herein may be used to secure any hollow component to be drilled.
Referring to
Template 130 may also be positioned on support structure 120. Template 130 may substantially surround component 102. More specifically, template 130 may substantially surround forward end 104 of component 102. As used herein, “substantially” refers to largely, for the most part, entirely specified or any slight deviation which provides the same technical benefits of the invention. Template 130 may be manufactured from, for example, a metal. In one embodiment, template 130 may include at least one arcuate plate. In some embodiments, template 130 may include four arcuate plates spaced evenly about component 102 on support structure 120. It is to be understood that template 130 may include any number of arcuate plates or may be one circumferential piece configured to surround component 102.
Template 130 is configured to locate a position on component 102 that is to be drilled. That is, template 130 may have at least one hole 132 therethrough which may accommodate a drill bit (not shown) of a drill 140 such that a drill bit may extend through the at least one hole 132 in template 130 in order to contact component 102 at a desired location on component 102 to be drilled. Additionally, in some embodiments, template 130 may include a pair of alignment holes 134 adjacent to the at least one hole 132 in template 130. Alignment holes 134 may be configured to accommodate a pair of alignment features (not shown) on drill 140. Drill 140 may include any drill known in the art capable of drilling a hole into component 102. In some embodiments, drill 140 may be, for example, but not limited to a compact automatic feed precision drill such as a Quakenbush™ drill.
Template 130 may include a pair of risers 138 to raise template 130 relative to support structure 120. Risers 138 may be used to adjust a height of template 130 such that the at least one hole 132 in template 130 is located at the desired position to be drilled on component 102. Risers 138 may be a fixed height or may be adjustable. Risers 138 may include, but are not limited to, blocks, wedges, shims or other structures capable of adjusting height of template 130.
Additionally, centering device 150 may further include a component support 156. Component support 156 may be adapted to engage back end 106 of component 102 thereby assisting in maintaining the position of component 102 on support structure 120. Component support 156 may maintain the position of component 102 by supplying a downward force such that component 102 is being pressed against support structure 120. Component support 156 may include, but is not limited to, for example: a clamp, brace, band, clasp, vice or press.
Referring back to
With reference to
A first step of the method may include providing a component 102 within a template 130 on a support structure 120 such that component 102 substantially surrounds a centering device 150 on support structure 120. As previously discussed, template 130 may have at least one hole 132 therethrough and template 130 may include at least one arcuate plate having at least one hole therethrough. Component 102 may be provided within template such that component 102 is adjacent to the at least one arcuate plate.
A second step of the method may include centering component 102 within template 130 via centering device 150. As previously discussed, centering device 150 may include component centering feature 152 having at least three legs 154 and a component support 156. The step of centering component 102 may include adjusting component centering feature 152 such that each of the three legs 154 simultaneously extend radially outward to engage a radially inner surface 108a of component 102. Component centering feature 152 may be similar to a scroll screw in that each leg 154 may simultaneously extend radially outward at the same rate such that a position of component 102 adjusts as a respective leg 154 places pressure on radially inner wall 108a of component when radially inner wall 108a is contacted by the respective leg 154. Once each leg is in contact 154 component 102, component 102 is maintained by the equal pressure placed radially outward about its radially inner wall 108a by each leg 154.
The step of centering component 102 may also include engaging a back end 106 of component 102 via component support 156 thereby assisting in maintaining the position of component 102 on support structure 120. Component support 156 may maintain the position of component 102 by supplying a downward force such that component 102 is being pressed against support structure 120. As previously discussed, component support 156 may include, but is not limited to, for example: a clamp, brace, band, clasp, vice or a press.
Another step of the method may include engaging component 102 with component locating feature 160. More specifically, component locating feature 160 may engage with a support 162 on component 102 to orient component 102 on support structure 120. Engaging component 102 with component locating feature 160 may further secure component 102 during drilling. That is, component locating feature 160 may lock into support 162 of component 102. As described with reference to
Another step of the method as described herein may include inserting a drill bit of drill 140 through the at least one hole 132 of the template 130 to drill a hole into component 102. In the case of component 102 being a transition piece 10 (
Once hole is drilled, component 102 may be removed from fixture 100. In the case where component 102 is a transition piece 10 (
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The corresponding structures, substantially materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, substantially material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiment was chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.
