IDLER ASSEMBLY, AND METHOD FOR RETROFITTING AN EXISTING IDLER ASSEMBLY

Technical Field

Background

Tracked vehicles, such as bulldozers, moveable cranes, and shovels utilize idler wheels. The idler wheel is typically mounted for rotation on a shaft, which in turn is fixedly mounted to the frame of the tracked vehicle. Unfortunately, such a mounting arrangement generally causes wear on the shaft at a region within the frame. This wear is often difficult to detect as it is hidden from view. The location of the wear region may also be difficult for providing regular maintenance to the shaft. Additionally, repair of the idler wheel is often extensive as the non-rotating shaft must be removed from the frame and replaced. Such a repair is both time consuming and expensive.

Summary of the Invention

In one embodiment, there is provided an idler assembly for a shovel having a flexible track assembly, the idler assembly comprising an idler gear having an inner portion and an outer portion, the inner portion forming an opening therethrough, and the outer portion operatively associated with the flexible track assembly; a sleeve having an inner surface and an outer surface in opposition to one another, the inner surface of the sleeve forming an inner diameter, a set of splines disposed on the inner surface, and the outer surface of the sleeve forming an outer diameter sized for attachment within the inner portion of the idler gear; a shaft having an outer portion with a set of splines thereon, the outer portion sized for placement within the inner diameter of the sleeve, the set of splines of the shaft and the set of splines of the sleeve sized for engagement with one another, and connectors disposed at opposed ends of the shaft; at least one bearing block in attachment to a frame assembly of the shovel, each of the at least one bearing block forming

a bore therethrough; at least one bushing liner disposed within the at least one bearing block, respectively, each of the at least one bushing liner having an inner surface and an outer surface in opposition to one another, the inner surface of each of the at least one bushing liner forming an inner diameter sized for placement of the shaft therein, and the outer surface of each of the bushing liners forming an outer diameter sized for placement within the bore of each of the at least one bearing block; and at least one retaining device for constraining the shaft from withdrawal from the bore of the at least one bearing block, the at least one retaining device in removable attachment to the connectors disposed at opposed ends of the at least one bearing block, respectively, wherein the shaft rotates within the at least one bearing block as the idler gear rotates in response to movement of the flexible track assembly.

In another embodiment, there is provided a method for retrofitting a shovel with a flexible track assembly from an existing idler assembly to an improved idler assembly, the method comprising positioning at least one bushing liner within a bore of at least one bearing block, respectively; attaching an idler shaft and an idler gear together with one another, wherein the shaft rotates together with the idler gear; and positioning a first portion and a second portion of the idler shaft within the at least one bushing liner positioned within the bore of the at least one bearing block , and the first portion and the second portion disposed on opposing sides of the idler gear in attachment thereto.

In yet another embodiment, there is provided a method for method for retrofitting a shovel with a flexible track assembly from an existing idler assembly to an improved idler assembly, the method comprising removing a non-rotating shaft from bearing blocks in attachment to a frame assembly of the shovel, and from an idler gear operatively associated therewith; boring an enlarged opening through the idler gear, wherein the enlarged opening is sized for attachment of a sleeve therein; boring enlarged openings through the bearing blocks, respectively, wherein the enlarged openings are each sized for placement of a bushing liner in the bearing blocks, respectively; attaching the sleeve to an inner portion of the idler gear; placing the sleeve and the idler gear between the bearing blocks; placing a shaft through the

enlarged openings of the bearing blocks and through the sleeve in attachment to the inner portion of the idler gear, wherein the shaft and the sleeve each comprise a set of splines that mate with one another; and attaching a retaining device to each one of the ends of the shaft, wherein the retaining device constrains the shaft from withdrawal from the bores of each one of the bearing blocks.

In still another embodiment, there is provided a kit for retrofitting a shovel with a flexible track assembly, the kit comprising a sleeve having an inner surface and an outer surface in opposition to one another, the inner surface of the sleeve forming an inner diameter, a set of splines disposed on the inner surface, and the outer surface of the sleeve forming an outer diameter sized for attachment within the inner portion of the idler gear; a shaft having an outer portion with a set of splines thereon, the outer portion sized for placement within the inner diameter of the sleeve, the set of splines of the shaft and the set of splines of the sleeve sized for engagement with one another, and connectors disposed at opposed ends of the shaft; at least one bushing liner for disposal within a bore formed in at least one bearing block, each of the at least one bushing liner having an inner surface and an outer surface in opposition to one another, the inner surface of the at least one bushing liner forming an inner diameter sized for placement of the shaft therein, and the outer surface of the at least one bushing liner forming an outer diameter sized for placement within the bore of the at least one bearing block; and at least one retaining device for constraining the shaft from withdrawal from the bore of the at least one bearing blocks, the at least one retaining device for removable attachment to the connectors disposed at opposed ends of the at least one bearing block, respectively, wherein the shaft rotates within the at least one bearing block as the idler gear rotates in response to movement of the flexible track assembly.

In another embodiment, there is provided an idler assembly for idler assembly for a shovel having a flexible track assembly, the idler assembly comprising an idler gear operatively associated with the flexible track assembly; a shaft fixedly connected to the idler gear, the shaft having a first portion and a second portion on opposed sides of the idler gear, wherein the

shaft rotates together with the idler gear; and at least one bearing block in attachment to a frame assembly of the shovel, each of the at least one bearing blocks forming a bore therethrough, and at least one of the first portion and the second portion of the shaft extending through the at least one bearing block.

Other embodiments are also disclosed.

Brief Description of the Drawings

Illustrative embodiments of the invention are illustrated in the drawings, in which:

FIGURE 1 is a diagrammatic illustration of a rotatable idler shaft assembly of an embodiment, an idler gear and the rotatable idler shaft are fixedly attached to one another, and the ends of the rotatable idler shaft are disposed in brass bushings in bearing blocks;

FIGURE 2 is a diagrammatic illustration of an idler gear having an opening for attachment to a sleeve and a shaft;

FIGURE 3 is a diagrammatic illustration of an idler gear having an opening with a set of splines for attachment to a shaft having a set of splines;

FIGURE 4 is an illustration of a shaft with splines for selective attachment of the idler gear with the shaft, and a pair of radial recesses disposed at opposed end of the shaft for attachment of a retainer thereto; FIGURES 5 and 6 are illustrations of an attachment sleeve having splines formed on the inner wall for attachment to splines formed on a rotatable shaft, and the outer wall of the sleeve and the opening of the idler gear sized for attachment to one another;

FIGURE 7 is a diagrammatic illustration of a bearing block having a bore sized to accommodate a rotatable idler shaft therein together with bushing material;

FIGURES 8-10 are diagrammatic illustrations of a brass bushing configured for placement between the idler block and the idler shaft;

FIGURE 11 is a diagrammatic illustration of a split collar retainer sized

for attachment with the end of the idler shaft and to provide an axial thrust area to constrain axial movement of the shaft through each of the brass bushings;

FIGURES 12-16 are flow chart diagrams illustrating methods for retrofitting a shovel with an improved idler assembly; and

FIGURE 17 is a kit for retrofitting a shovel with a flexible track assembly.

Detailed Description of an Embodiment

Referring to FIGURE 1 , and in an embodiment, there is shown an idler assembly 100 for a shovel having a flexible track assembly. Generally, idler assembly 100 includes an idler gear 105, a sleeve 110, a shaft 115, at least one bearing block 120, at least one bushing liner 125, and at least one retaining device 130.

Idler shaft 105 of idler assembly 100 rotates to provide enhanced component life in contrast with a fixed idle shaft of an idler assembly. This reduces unplanned maintenance and may allow easier inspection for wear of idler shaft 115 than idler shaft 35. Referring now to FIGURES 1, 2, and 3, there is shown idler gear 105 having an inner portion 135 and an outer portion 140. An opening 145 is formed through inner portion 135. Outer portion 140 is operatively associated with a flexible track assembly.

Referring to FIGURE 2, and in an embodiment, sleeve 110 may be secured within opening 145 of idler gear 135. In one embodiment, sleeve 110 and idler gear 105 have a metal to metal fit. Optionally, sleeve 110 and idler gear 105 are welded together.

Referring to FIGURE 3, and in an embodiment, a set of splines 165 may be disposed within opening 145 of idler gear 135. In one embodiment, shaft 115 and idler gear 135 may be joined directly to one another.

Referring to FIGURES 1 , 5 and 6, there is shown sleeve 110 having an inner surface 150 and an outer surface 155 in opposition to one another. Inner surface 150 of sleeve 110 may form an inner diameter 152. A set of

splines 160 may be disposed on inner surface 150. Outer surface 155 of sleeve 110 may form an outer diameter 165 sized for attachment within inner portion 135 of idler gear 105.

Referring to FIGURE 4, there is shown shaft 115 having an outer portion 170 with a set of splines 175 thereon. In an embodiment, outer portion 170 is sized for placement within inner diameter 165 of sleeve 110. The set of splines 175 of shaft 115 and the set of splines 160 of sleeve 110 may be sized for engagement with one another. In an embodiment, a pair of connectors 180 may be disposed at opposed ends 185, 190 of shaft 115. Referring to FIGURES 1 and 7, there is shown bearing block 120 which is generally in attachment to the frame assembly of the shovel. A bore 195 extends through each of one of the at least one bearing block 120. In one embodiment, a counterbore 197 is formed in bearing block 120.

Referring to FIGURES 1 , and 8-10, there is shown one of the at least one bushing liner 125 for disposal within the at least one bearing block 120. Each bushing liner 125 has an inner surface 200 and an outer surface 205 in opposition to one another. Inner surface 200 of each one of the at least one bushing liner 125 forms an inner diameter 210 sized for placement of shaft 115 therein. Outer surface 205 of each of the at least one bushing liner 125 forms an outer diameter 215 sized for placement within bore 195 of each one of the pair of bearing blocks 120.

Referring to FIGURES 1 and 11 , there is shown the pair of retaining devices 130 for constraining shaft 115 from withdrawal from bore 195 of each one of bearing blocks 120. In an embodiment, the at least one retaining device 130 may be in removable attachment to connectors 180 disposed at opposed ends 185, 190 of bearing blocks 120, respectively. Shaft 115 rotates within bearing block 120 as idler gear 105 rotates in response to movement of flexible track assembly 10. In an embodiment, the at least one retaining device 130 may rotate with shaft 115. In an embodiment, grooves 180 (FIGURE 4) may form the connectors

180 at opposed ends 185, 190 of shaft 115. In one embodiment, the at least one retaining device 130 may comprise at least two split collar retainers 130 (FIGURE 11), which may include a pair of half-rings 131 attached by bolts

132 and nuts 133. In an embodiment, split collar retainers 130 rotate in attachment with shaft 115.

Referring to FIGURE 5, and in an embodiment, sleeve 110 may comprise a beveled edge 220 at opposed ends 225, 230. Beveled edge 220 may provide a recess between sleeve 110 and idler gear 105. For example, beveled edge 220 may extend at a 45 degree angle from inner surface 150. A weld may be placed in the recess formed by beveled edge 220. This weld may be formed, for example, by stainless wire or electrode, and may also be blended to finish the surface. In an embodiment, the set of splines 160 may extend the full length of sleeve 110. In one embodiment, the set of splines 160 may over a portion of sleeve 160 and be set back at each end. Optionally, ends of the set of splines 160 may be tapered inwardly for ease of assembly.

Looking at FIGURE 12, and in an embodiment, there is provided a method 235 for retrofitting shovel 5 with flexible track assembly 10 from an existing idler assembly 15 to an improved idler assembly 100. Method 235 generally comprises positioning 240 pair of bushing liners 125 within bores 195 of the pair of bearing blocks 120, respectively. Method 235 generally comprises attaching 245 idler shaft 115 and idler gear 105 together with one another, wherein shaft 115 rotates together with idler gear 105. Method 235 generally comprises positioning 250 a first portion and a second portion of idler shaft 115 within bushing liners 125 positioned within bores 195 of bearing blocks 120, respectively, and the first portion and the second portion disposed on opposing sides of idler gear 105 in attachment thereto. Referring to FIGURE 13, and in an embodiment, there is provided a method 255 which includes method 235 and further comprises boring 260 through idler gear 105 to provide an enlarged opening 265 therethrough. Enlarged opening 265 may be sized for attachment of sleeve 110 therein. Referring to FIGURE 14, and in an embodiment, there is provided a method 270 which includes method 235 and further comprises boring 275 an enlarged opening 280 through bearing blocks 120. Enlarged opening 280 may be sized for placement of bushing liners 125 therein.

Referring to FIGURE 15, and in an embodiment, there is provided a method 285 which includes method 270, bearing blocks 120 each have an inner portion 290 and an outer portion 295 in opposition to one another, and inner portion 290 is disposed toward idler gear 105. Method 285 further comprises boring 300 a countersink 305 at outer portion 295 of opening 280 of bearing blocks 120 prior to positioning pair of bushing liners 125 within bores 195 of pair of bearing blocks 120. In an embodiment, countersinks 305 provide an area for disposition of a thrust flange 310 extending from bushing liner 125. Looking at FIGURE 16, and in one embodiment, there is provided a method 315 for retrofitting a shovel with flexible track assembly from an existing idler assembly to an improved idler assembly.

Method 315 generally comprises removing 320 a non-rotating shaft from the pair of bearing blocks in attachment to the frame assembly of the shovel, and from the idler gear operatively associated therewith. Method 315 generally comprises boring an enlarged opening through the idler gear. Enlarged opening 265 may be sized for attachment of sleeve 110 therein. Method 315 generally comprises boring 330 enlarged openings 280 through bearing blocks 120, respectively. Enlarged opening 280 may be sized for placement of bushing liners 125 in bearing blocks 120, respectively.

Method 315 generally comprises attaching 335 sleeve 110 to inner portion 135 of idler gear 105. Method 315 generally comprises placing 340 sleeve 110 and idler gear 105 between the pair of enlarged openings 280 of the pair of bearing blocks 120. Method 315 generally comprises placing 345 shaft 115 through the pair of enlarged openings 280 of the pair of bearing blocks 120 and through sleeve 110 in attachment to inner portion 135 of idler gear 105. Sleeve 110 and shaft 115 may each comprise a set of splines 160, 175 that mate with one another, respectively. Method 315 generally comprises attaching 350 retaining devices 130 to each one of the ends 185, 190 of shaft 115. Retaining devices 130 may constrain shaft 115 from withdrawal from bores 195 of each one of bearing blocks 120.

Looking at FIGURE 17, and in one embodiment, there is provided a kit 355 for retrofitting shovel 5 with a flexible track assembly. Kit 355 may comprise sleeve 110, shaft 115, bushing liners 125, and retaining devices 130. In an embodiment, connectors 180 comprise grooves 180 formed in the opposed ends of shaft 115. In one embodiment, the pair of retaining devices 130 in kit 355 comprise the pair of split collar retainers 130. In an embodiment, the material hardness of bushing liners 125 is less the material hardness of shaft 115. In one embodiment, the material hardness of bushing liners 125 is less than the material hardness of bearing blocks 120. In an embodiment, there is provided an idler assembly for a shovel having flexible track assembly. Generally, the idler assembly may comprise idler gear 105, shaft 115, bearing blocks 120, bushing liners 125, and retaining devices 130.

Idler gear 105 may be operatively associated with flexible track assembly. Shaft 115 is fixedly connected to idler gear 105. Shaft 115 has a first portion and a second portion on opposed sides of the idler gear 105 such that the shaft 115 rotates together with idler gear 105.

Bearing blocks 120 may be in attachment to the frame assembly of the shovel. Each of bearing blocks 120 may form bore 195 therethrough. The first portion and the second portion of shaft 115 may each extend through one of bearing blocks 120, respectively.

Bushing liners 125 may be disposed within bores 195 of bearing blocks 120, respectively. Each of bushing liners 125 may have inner surface 150 and outer surface 155 in opposition to one another. Inner surface 150 of each of the bushing liners 125 may form inner diameter 210 sized for placement of shaft 115 therein. Outer surface 155 of each of bushing liners 125 may form outer diameter 215 sized for placement within bore 195 of each of the pair of bearing blocks 120.

Retaining devices 130 are provided for constraining shaft 115 from withdrawal from bore 195 of each one of the bearing blocks 120. Shaft 115 may rotate within the bearing blocks 120 as idler gear 105 rotates in response to movement of the flexible track assembly 10.