SYSTEM AND METHOD FOR SALVAGING A PIN-BORE ASSEMBLY

A method for salvaging a surface of a pin-bore assembly associated with a carrier is provided. The method includes inserting a sleeve within a bore of the carrier. The method also includes installing a retention mechanism that secures the sleeve within the bore of the carrier.

TECHNICAL FIELD

The present disclosure relates to a system and method for salvaging of wear prone surfaces, more particularly to the system and method for salvaging a pin-bore assembly of a carrier.

BACKGROUND

A pin bore of a final drive carrier that is configured to receive a pin may be subjected to wear and tear. This may cause oversizing of a diameter of the bore which in turn leads to the carrier being unusable. Known salvaging methods for the bore of the carrier include heating the bore using a high temperature heat source. Heating the metal of the bore may expand a metal used to form the carrier, thereby decreasing the bore diameter. However, this salvaging method may allow the carrier to be reused only once.

U.S. Pat. No. 4,153,983 discloses a cylinder wall repair wherein worn or damaged areas of the cylinder are restored. The cylinder housing is re-bored and threaded or ground. An externally threaded or grooved sleeve member is then screwed or inserted into the cylinder housing. The internal configuration and dimensions of the sleeve member may be designed to duplicate that of the original cylinder. The thread or groove design provides tunnels between the sleeve member and the cylinder housing.

SUMMARY OF THE DISCLOSURE

In one aspect of the present disclosure, a method for salvaging a surface of a pin-bore assembly associated with a carrier is provided. The method includes inserting a sleeve within a bore of the carrier. The method also includes installing a retention mechanism that secures the sleeve within the bore of the carrier.

In another aspect of the present disclosure, a carrier including a front wall and a rear wall is provided. The carrier also includes a pin-bore assembly provided on the front and rear walls of the carrier. Further, the pin-bore assembly includes a sleeve press fitted within a bore defined by an inner surface of the carrier. The pin-bore assembly also includes a retention mechanism that secures the sleeve within the bore of the carrier.

DETAILED DESCRIPTION

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts.FIG. 1illustrates a perspective view of the carrier102according to an embodiment of the present disclosure.FIG. 1includes cutting planes AA and BB. In the illustrated embodiment, the carrier102has a circular configuration. The carrier102may be used in a final drive assembly (not shown) associated with an engine assembly (not shown). The carrier102includes a front wall104. In one embodiment, the carrier102may also include a rear wall106. Further, the rear wall106of the carrier102may include a circumferential extension112. The extension112may have a plurality of holes114provided along a circumference of the extension112in order to attach the carrier102to another engine component.

The front and rear walls104,106of the carrier102may be connected by a plurality of axial projections116. The projections116are provided along an axis XX defined by the carrier102. The carrier102also includes a central bore provided along the axis XX. The central bore may be configured to receive a shaft (not shown) of the final drive assembly. The front and rear walls104,106of the carrier102include a first bore119(seeFIG. 4) and a second bore120(seeFIG. 4) respectively. Further, the first and second bores119,120on the walls104,106of the carrier102are coaxial. The carrier102includes an inner surface121(seeFIG. 4) defining the first and second bores119,120of the carrier102. Referring toFIG. 1, a sleeve122is provided within the first and second bores119,120of the carrier102. A pin124may be received into the sleeve122. Only one pin124is illustrated inFIG. 1merely for the purpose of clarity.

FIG. 2is a perspective view of the sleeve122, according to one embodiment of the present disclosure. In one embodiment, the sleeve122may have a hollow cylindrical configuration. The sleeve122includes an inner surface206and an outer surface208. The inner surface206of the sleeve122defines a pin bore209, such that the pin bore209is configured to receive the pin124. The sleeve122may include a flange210extending from one end of the sleeve122. It should be noted that the sleeve122may be made from any metal known in the art.

FIG. 3illustrates a cut section along the cutting plane BB showing a pin-bore assembly of the carrier102. The pin-bore assembly includes the sleeve122inserted within the first and second bores119,120. The pin124is positioned within the pin bore209defined by the inner surface206of the sleeve122. In one embodiment, a bearing (not shown) may be located surrounding the pin124. Prior to assembly of the sleeve122, the first and second bores119,120(seeFIG. 4) of the carrier102are appropriately machined to cooperate with the outer surface208of the sleeve122.

As shown inFIG. 3, after assembly, the sleeve122is positioned between the pin124and the first and second bores119,120of the carrier102or at an interface of the pin124and the inner surface121of the carrier102in a manner such that the sleeve122may serve as a sacrificial surface during installation or removal of the pin124. It should be noted that the shape of the sleeve122positioned at the front and rear walls104,106of the carrier102may be different in order to accommodate the pin124. In the illustrated embodiment, the sleeve122on the front wall104of the carrier102has a substantially hollow cylindrical configuration. Whereas, the sleeve122on the rear wall106has a hollow cylindrical configuration with the flange210extending from one end of the sleeve122. As seen in the accompanying figure, the first bore119on the front wall104of the carrier102may have an enlarged diameter compared to that of the second bore120provided on the rear wall106of the carrier102in order to cooperate with and receive a stepped portion of the pin124.

Moreover, a plate308may be bolted onto either the front and/or rear walls104,106of the carrier102in order to securely fix the pin124inside the pin bore209defined by the sleeve122. In one embodiment, the plate308may have a circular configuration. It should be noted that the plate308may have a diameter greater than that of the diameter of the first and second bores119,120such that the plate308covers a circumference of the pin124and the sleeve122when assembled. In one embodiment, a thrust plate402(seeFIG. 4) may be attached to a surface of the front and/or rear walls104,106of the carrier102for contacting with the bearing. Based on the location of the thrust plate402on the carrier102, the flange210of the sleeve122may rest on the thrust plate402in order to reinforce the thrust plate402. In this situation, as shown inFIG. 3, the flange210associated with the sleeve122may come in contact with the bearing and act as a thrust face for the bearing.

In the present disclosure, the sleeve122is press fitted between the first and second bores119,120of the carrier102and the pin124. Also, a retention mechanism is provided to secure the sleeve122within the first and second bores119,120of the carrier102. The retention mechanism is configured to hold the sleeve122within the first and second bores119,120of the carrier102during the installation or the removal of the pin124. Different retention mechanisms include providing mechanical fasteners502(explained in connection withFIGS. 4 to 6) and welding (explained in connection withFIGS. 8 and 9), according to various embodiments of the present disclosure.

FIG. 4shows a cut section along the cutting plane AA depicting an exploded view of the sleeves122associated with the front and rear walls104,106of the carrier102respectively. As is clearly visible, the inner surface121of the front and rear walls104,106of the carrier102define the first and second bores119,120respectively therein. In the illustrated embodiment, the first bore119on the front wall104of the carrier102is machined to a certain depth in order to receive the flange210of the sleeve122. One of ordinary skill in the art will appreciate that any of the front or rear walls104,106may be appropriately machined for cooperating with a shape of the sleeve122to be inserted therein. Further, the thrust plate402is provided on the rear wall106of the carrier102.FIG. 5shows the assembled cut section view along the plane AA including the sleeve122fitted within the first and second bores119,120of the carrier102. When assembled, the flange210of the sleeve122is configured to rest on the thrust plate402. As mentioned earlier, the sleeve122may be retained within the first and second bores119,120using the mechanical fasteners502as the retention mechanism. The sleeve122may include a number of holes provided circumferentially on the flange210corresponding to holes provided on the carrier102for receiving the mechanical fasteners502. The mechanical fasteners502may include a bolt, stud, rivet, and the like.

FIG. 6shows another arrangement of the mechanical fastener502along the cutting plane BB. The design of the sleeve122in this figure is different from that shown inFIGS. 2,4and5. More particularly, the sleeve122may have a hollow cylindrical configuration. Also, the positioning of the mechanical fasteners502is different from that shown inFIG. 5. An outer periphery of the sleeve122may include the holes in such a manner that a diameter of the hole is partially provided on the outer periphery of the sleeve122and a remaining portion of the hole is provided on the carrier102. The plurality of holes on the sleeve122and the walls104,106of the carrier102are configured to receive the mechanical fastener502, such as, for example, a set screw.

In one embodiment, an adhesive may be applied on the outer surface208of the sleeve122prior to insertion of the sleeve122into the first and second bores119,120of the carrier102. Similarly, the adhesive may also be applied on the inner surface121of the carrier102which is configured to receive the sleeve122. It should be noted that the adhesive is applied to freeze the sleeve122prior to the insertion for attaining the desired press fit between the first or second bores119,120and the sleeve122. In another embodiment, the adhesive may be provided on an outer surface of the mechanical fastener502. Additionally, the adhesive may be applied on an inner surface of the holes provided on the sleeve122and the front and/or rear walls104,106of the carrier102for holding the mechanical fastener502in position therein.

FIG. 7is a perspective view of another design of the sleeve122, according to one embodiment of the present disclosure. In this design, the sleeve122includes a stepped portion702. The sleeve122also includes a beveled surface704machined on an outer periphery of the stepped portion702.

FIG. 8is an exploded view along the cutting plane AA showing the carrier102and the sleeve122depicted inFIG. 7. In the embodiment illustrated inFIGS. 8 and 9, the retention mechanism includes welding the sleeve122to the front and rear walls104,106of the carrier102. Referring toFIG. 8, the inner surface121of the carrier102is shaped to receive the sleeve122. More particularly, the inner surface121of the carrier102also includes a beveled surface802machined along an edge of the front and rear walls104,106of the carrier102to cooperate with the beveled surface704of the sleeve122.

FIG. 9shows an assembled view of the arrangement ofFIG. 8provided along the cutting plane AA. The sleeve122is provided within the carrier102such that the beveled surfaces704,802of the sleeve122and the carrier102form a groove902configured to receive a weld bead904for welding the sleeve122with the carrier102. After the sleeve122is press fitted into the carrier102, a diameter of the pin bores209defined by the inner surface206of the sleeve122on the front and rear walls104,106respectively may be aligned for receiving the pin124.

INDUSTRIAL APPLICABILITY

The bores of the carrier may get oversized due to wear and tear, thereby rendering the carrier as unusable. Known salvaging methods include using a high temperature heat source to heat the oversized bore to cause a reduction in diameter of the bore for re-use. However, employing such methods allows for the re-use of the carrier only once.

A system and method for salvaging the first and second bores119,120of the carrier102is disclosed herein. The sleeve122is press fitted between the first and second bores119,120of the carrier102and the pin124. The pin124may be received into the pin bore209defined by the sleeve122. Further, the retention mechanism is provided to hold the sleeve122in place during the installation and the removal of the pin124. In a situation wherein the pin bore209of the sleeve122may get oversized, the sleeve122may be replaced. Hence, the first and second bores119,120of the carrier102may remain protected or intact, allowing for multiple re-use.

FIG. 10illustrates a method1000for salvaging the surface of the pin-bore assembly associated with the carrier102. At step1002, the sleeve122is inserted within the first and second bores119,120of the carrier102. The first and second bores119,120of the carrier102are machined prior to the insertion in order to receive the sleeve122so that the outer surface208of the sleeve122conforms to the first and second bores119,120.

Further, in one embodiment, the adhesive is provided on the inner surface121of the carrier102to control the press fit between the sleeve122and the first and second bores119,120of the carrier102. In another embodiment, the adhesive may be provided on the outer surface208of the sleeve122prior to insertion within the first and second bores119,120. The sleeve122may be frozen before inserting the sleeve122within the first and second bores119,120of the carrier102in order to control the press fit between the sleeve122and the first and second bores119,120of the carrier102.

At step1004, the retention mechanism associated with the sleeve122is installed. As explained earlier, the retention mechanism is provided in order to secure the sleeve122within the first and second bores119,120of the carrier102during the installation or the removal of the pin124. In one embodiment, the holes may be provided on the outer periphery of the flange210and the walls104,106of the carrier102respectively. The holes are configured to receive the mechanical fasteners502for affixing the sleeve122onto the carrier102. In another embodiment, the holes are provided partially on the outer periphery of the sleeve122and partially on the walls104,106of the carrier102.

Further, in order to provide a better fastening, the adhesive may be applied on the mechanical fasteners502prior to insertion within the holes of the sleeve122and carrier102. The adhesive may also be applied within the holes of the sleeve122and/or the carrier102. It should be noted that the adhesive may be used to increase retention strength between the sleeve122and the first and second bores119,120of the carrier102.

An alternative retention mechanism may also be utilized such that the weld bead904may be provided within the groove902defined along the edge of the walls104,106of the carrier102and the sleeve122. Further, the pin bore209defined by the sleeve122on the front wall104of the carrier102and the corresponding pin bore209on the rear wall106of the carrier102is aligned. The pin bores209may be aligned in order to receive the pin124. The aligning of the pin bores209may includes machining the inner surface206of the sleeves122installed on the front and rear walls104,106of the carrier102, such that the diameters of the pin bores209on the respective walls104,106are coaxial and cooperate with one another for receiving the pin124.

Additional machining of the sleeve122and/or the walls104,106may be performed for final shaping and cooperation with the carrier102. For example, after the installation of the sleeve122therein, the front and rear walls104,106and the sleeve122may be machined in order to remove excessive material and form a smooth surface on the respective walls104,106.