It is common that machinery is made of functional modules that attach to each other usually by means of bolts, clamps, screws and the like. Common openings between modules may allow for the transfer of fluids such as gasses or liquids, and mechanical, electrical or other types of energy to enable adjacent modules to cooperate.
If the modules are separated, it is important that the areas that link the modules together are not damaged to avoid leaks, contamination, inefficiencies or the like.
If an edge of a circular opening, for instance, gets nicked, it is typical to machine the bore of the opening to remove enough material to eliminate the damage. A bead or an insert is then welded to the bore to rebuild the bore of the opening to its initial tolerance.
According to an embodiment disclosed herein, a shim is provided for repairing damage in a surface of a mechanical piece at or near an outer edge of a bore in the surface. The damage may penetrate a given distance within the surface and the bore is in close proximity to an attachment hole. The shim has a body having a first side and a second side and a thickness therebetween that is equal to or greater than the depth of the damage penetrating the given distance and contiguous to the attachment opening, wherein the body fits within an area machined into an outer surface surrounding the bore.
According to a further embodiment disclosed herein, an assembly for repairing damage in a gas turbine engine includes a gas turbine engine component that has a bore and a machined area disposed on an outside surface of the component contiguous to the bore. The machined area has a first depth equal to or greater than a depth of damage to the component. A shim has a body having a first side and a second side and a thickness therebetween that is equal to the first depth, wherein the body fits within the machined area and is flush thereto.
According to a further embodiment disclosed herein, a method of repairing damage in a gas turbine engine component includes: locating damage in a surface of the component in proximity to or within an edge of a bore; machining an area into an outer surface of the component in proximity to and touching the bore to a first depth that is equal to or greater than a depth of the damage in the outer surface; and inserting a shim into the area, the shim having a body having a first side and a second side and a thickness therebetween that is equal to the first depth wherein the shim is flush with the surface.
The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.
Referring to
Referring now to
In the past, the bore diameter D was machined out the distance N2 to eliminate the nick, but the Applicants have discovered that there are two distinct problems with such actions: it can be seen in
In the disclosed embodiment, instead of machining out the bore 45, an area 55 corresponding to the shape of a shim 60 (see also
Referring now to
The body 70 may have a plurality flanges 85 disposed around the outer edges 90 of the body. The area 55 may have a deeper opening 95 machined therein for receiving the flanges 85 therein. The flanges 85 and openings 95 act to locate the ship properly within the area 55.
Referring to the
The shim 60 and its lobes 75 may take many shapes and may repair more than one nick 35 on more than one bore 45. For instance, shim 105 about opening 21 has an ovate shape with two holes 80. Shim 110 is circular and has a plurality of crafted lobes 75 extending outwardly from the body 70 of the shim 60. Shim 115, which is seen in
The shim 60 material may also be crafted by constructing or coating it with different materials or coatings to enhance the functionality of the gear box 10. For instance, if the second half (not shown) of the gearbox 10 or other connectors (not shown) are made of a hard material, relative motion therebetween tends to damage the gearbox that is constructed of generally softer magnesium or aluminum. The shim 60 may be coated or constructed of a harder material such as an oxide, or coated with a lubricious material such as PTFE. The shim 60 may also be coated with a thermal spray or a PVD coating. If electrical resistance between the parts is desired, the shim may be made of an oxide or painted. Similarly if electrical resistance between the parts is not desired, the shim may be made of or coated with an inorganic material or anodized. Also, the part may have an inert coating for chemical resistance. Other coatings and materials for the shim 60 are contemplated herein depending on the shim environment and the types of parts used therewith.
Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.
This invention was made with Government support under F33657-99-D-2051 awarded by The United States Air Force. The Government has certain rights in this invention.