ASSEMBLY GUIDE FOR SLEEVED PLANETARY CARRIERS

Abstract

A method for assembling a carrier subassembly for use with a planetary gear train comprises inserting a gear so that the bore of the gear surrounds the bore of the carrier member, and aligning an assembly guide having a bore by engaging a portion of the assembly guide with an alignment feature of the carrier subassembly such that the bore of the assembly guide is aligned with the bore of the carrier member.

Claims

1. A carrier subassembly for use with a planetary gear assembly, the subassembly comprising: a carrier member that defines at least one bore that defines an inner surface and a surface that surrounds the bore of the carrier member; a gear that defines a bore that is concentric with the bore of the carrier member, the bore of the gear also defining an inner face; an axle that is operatively associated with the carrier member and the gear; and a sleeve that includes a cylindrical tube that defines a bore that is inserted into the bore of the carrier member, wherein the bore of the sleeve is concentric with the bore of the carrier member, and an end portion of the sleeve is proud compared to the surface surrounding the bore of the carrier member.

2. The subassembly of claim 1 further comprising an assembly guide that defines a first end and a second end and an aperture therethrough, wherein the first end of the guide defines a guide feature that is configured to contact a portion of the axle as the axle is inserted into the assembly guide and the second end of the guide defines an alignment feature that is configured to engage the proud portion of the sleeve.

3. The subassembly of claim 2 wherein the guide feature comprises a chamfered surface.

4. The subassembly of claim 2 wherein the alignment feature is a pocket defined by the second end of the guide that receives the proud portion of the sleeve, wherein the proud portion of the sleeve defines an outer cylindrical surface and the pocket defines an inner surface that is complimentary shaped to contact the outer cylindrical surface of the sleeve, aligning the bore of the sleeve to the aperture of the guide.

5. The subassembly of claim 1 wherein the carrier member includes an upper deck with an upper surface and a lower surface and the bore of the carrier member is an upper bore defined by the upper deck passing through the upper surface to the lower surface, and the sleeve further comprises a flange that extends from the cylindrical tube and contacts the lower surface of the upper deck.

6. The subassembly of claim 1 wherein the carrier member includes a lower deck with an upper surface and a lower surface and the bore of the carrier member is a lower bore defined by the lower deck passing through the upper surface to the lower surface, and the sleeve further comprises a flange that extends from the cylindrical tube and contacts the upper surface of the lower deck.

7. The subassembly of claim 1 wherein the axle defines a flange and a shaft, the subassembly further comprising a bearing or a bushing that defines a outer surface and an inner surface wherein the outer surface is configured to contact the inner surface of the gear and the inner surface is configured to mate with shaft of the axle.

8. The subassembly of claim 1 wherein the bearing or bushing is a roller bearing.

9. The subassembly of claim 8 further comprising a second bearing that is identical to the first bearing.

10. The subassembly of claim 9 wherein the gear is a planetary gear.

11. An assembly guide comprising: a generally cylindrical body that defines a cylindrical axis, a radial direction, a first end, a second end, and an aperture that extends from the first end to the second end along the cylindrical axis; wherein the first end includes a lead-in feature and the second end defines an alignment feature and the lead-in feature extends further in the outward radial direction than the alignment feature.

12. The assembly guide of claim 11 wherein the lead-in feature includes a chamfered surface and the alignment feature is a pocket defined by the second end of the assembly guide.

13. A method for assembling a carrier subassembly for use with a planetary gear train, the method comprising: inserting a gear so that the bore of the gear surrounds the bore of the carrier member; and aligning an assembly guide having a bore by engaging a portion of the assembly guide with an alignment feature of the carrier subassembly such that the bore of the assembly guide is aligned with the bore of the carrier member.

14. The method of claim 13 further comprising inserting an axle into the bore of the assembly guide until the shaft of the axle is concentric with the bore of the gear.

15. The method of claim 14 further comprising continuing to insert the axle until its flange contacts the assembly guide.

16. The method of claim 15 further comprising continuing to insert the axle until its shaft or flange contacts the sleeve.

17. The method of claim 13 wherein any inserting step comprises a pressing operation.

18. The method of claim 13 further comprising inserting a sleeve having a bore into the bore of the carrier member and wherein the aligning step includes engaging the assembly guide with a portion of the sleeve after the sleeve has been inserted into the bore of the carrier member.

19. The method of claim 17 further comprising exerting force on the flange.

20. The method of claim 13 further comprising removing the assembly guide from the carrier subassembly.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a perspective view of a planetary gear train carrier as is known in the art.

[0014] FIG. 2 is a cross-sectional view of a planetary gear train that is known in the art showing a first step used in assembling the gear train as the shaft is inserted through the bore of the carrier and begins to pass through the bore of a bearing race.

[0015] FIG. 3 shows step two of the assembly process depicted in FIG. 2 wherein the shaft has essentially passed through the bores of two bearing races arranged in concentric fashion adjacent each other.

[0016] FIG. 4 illustrates the final step of assembling the shaft into the carrier where the flange of the shaft is inserted into the upper bore of the carrier and the body of the shaft is inserted into the lower bore of the carrier.

[0017] FIG. 5 is cross-sectional view of a planetary gear train that uses a sleeve and an assembly guide for attaching the shaft to the gear train according to an embodiment of the present disclosure. As shown, the first step of the assembly process involves starting to insert the body of the shaft into the bore of a first race bearing.

[0018] FIG. 6 illustrates step two of the assembly process of FIG. 5 where the body of the shaft has been inserted into the bore of the second bearing race and the flange engages the lead-in surface of the assembly guide.

[0019] FIG. 7 depicts the third step of the assembly process where the body of the shaft has been inserted into the lower bore of the carrier and the flange of the shaft has been inserted into the bore of the sleeve.

[0020] FIG. 8 is an enlarged detail view showing more clearly how the assembly guide is located by the upper sleeve, guiding the flange of the axle into engagement with the inner surface of the bore of the upper sleeve.

[0021] FIG. 9 is a flow chart illustrating a method for assembling a planetary gear train.

DETAILED DESCRIPTION

[0022] Reference will now be made in detail to embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In some cases, a reference number will be indicated in this specification and the drawings will show the reference number followed by a letter for example, 100a, 100b or a prime indicator such as 100, 100 etc. It is to be understood that the use of letters or primes immediately after a reference number indicates that these features are similarly shaped and have similar function as is often the case when geometry is mirrored about a plane of symmetry. For ease of explanation in this specification, letters or primes will often not be included herein but may be shown in the drawings to indicate duplications of features discussed within this written specification.

[0023] This disclosure provides an improved structure and method of assembly when remanufacturing or manufacturing carrier subassemblies used with planetary gear trains and the like. In some cases, worn out surfaces may be replaced. In other cases, simply the assembly time and the precision of the assembled rotational joint are improved.

[0024] Looking now at FIG. 5, a carrier subassembly 200 for use with a planetary gear assembly 100 according to an embodiment of the present disclosure is shown. The carrier subassembly 200 may comprise a carrier member 202 that defines at least one bore 204 that defines an inner surface 208 and a surface 246 that surrounds the bore 204 of the carrier member 202. The subassembly 200 may further comprise a gear 236 that defines a bore 238 that is concentric with the bore 204 of the carrier member 202, the bore 238 of the gear 236 also defining an inner face 248. An axle 230 that is operatively associated with the carrier member 202 and the gear 236 is shown that allows the gear 236 to rotate relative to the carrier member 202. Also, a sleeve 250 is provided that includes a cylindrical tube 252 that defines a bore 254 that is inserted into the bore 204 of the carrier 202, wherein the bore 254 of the sleeve 250 is concentric with the bore 204 of the carrier 202, and an end portion 256 of the sleeve 250 is proud compared to the surface 246 surrounding the bore 204 of the carrier 202. This amount that the sleeve 250 protrudes past the upper surface 246 of the upper deck 216 of the carrier member 202 may range from 3-4 mm but this distance may be varied as needed or desired.

[0025] FIG. 5 also shows that an assembly guide 258, which defines a first end 260 and a second end 262 and an aperture 264 therethrough, may be provided. The first end 260 of the guide 260 defines a guide feature 266 that is configured to contact a portion of the axle 230 as the axle member 230 is inserted into the assembly guide 258 and the second end 262 of the guide 258 defines an alignment feature 268 that is configured to engage the proud portion 256 of the sleeve 250. The guide feature 266 may comprises any lead-in surface but is shown to be a chamfered surface 270 for this embodiment.

[0026] Looking at FIGS. 5 and 8 together, the alignment feature 268 is a pocket 272 defined by the second end 262 of the guide 258 that receives the proud portion 256 of the sleeve 250, wherein the proud portion 256 of the sleeve 250 defines an outer cylindrical surface 274 and the pocket 272 defines an inner surface 276 that is complimentary shaped to contact the outer cylindrical surface 274 of the sleeve 250, aligning the bore 254 of the sleeve 250 to the aperture 264 of the guide 258. The guide member 258 may be further characterized as having a generally cylindrical body 278 that defines a cylindrical axis A, a radial direction R, a first end 260, a second end 262, and a bore 264 that extends from the first end 260 to the second end 262 along the cylindrical axis A. As best seen in FIG. 8, the lead-in feature 266 extends further in the outward radial direction R than the alignment feature 268. The bottom 280 of the pocket 272 of the guide 258 is spaced away from the end portion 256 of the sleeve 250, providing clearance. The pocket 272 has a substantially rectangular configuration in the axial cross-section shown. Its width in the radial direction substantially matches the thickness of the cylindrical tube 252 of the sleeve 250 and may range from 2 to 4 mm. The height of the pocket, from end 262 of the guide member 258 to the bottom 280 of the pocket 272, measured along the cylindrical axis A, may range from 8 to 12 mm. Any of the dimensions or configurations of the guide member may be altered as needed or desired. A small chamfer or other lead-in feature 296 may be provided on the proud end 256 of the sleeve 250, which facilitates the placement of the assembly guide 258 onto the sleeve 250.

[0027] Focusing now on FIG. 5, the carrier member 202 includes an upper deck 216 with an upper surface 246 and a lower surface 282 and the bore 204 of the carrier is an upper bore 204 defined by the upper deck 216 passing through the upper surface 246 to the lower surface 282, and the sleeve 250 further comprises a flange 284 that extends from the cylindrical tube 252 and contacts the lower surface 282 of the upper deck 216. As a result, downward forced exerted on the axle 230 only serves to push the sleeve 250 downward onto the bearings 234, 234 and onto the lower sleeve 250 and the annular thrust surface 210 formed by flange 284 of that sleeve. To that end, the spacer ridge 286 provided on the interior of the gear 236 may be omitted to allow the downward force to press the upper sleeve 250, axle 230, bearings 234, 234 and lower sleeve 250 together. In such a case, the inner surface of the bore of the gear may be characterized as being continuous or uninterrupted from either longitudinal end of the gear.

[0028] In addition, the carrier member 202 includes a lower deck 218 with an upper surface 288 and a lower surface 290 and the bore 206 of the carrier member 202 is a lower bore 206 defined by the lower deck 218 passing through the upper surface 288 to the lower surface 290, and the lower sleeve 250 further comprises a flange 284 that extends from the cylindrical tube 252 and contacts the upper surface 288 of the lower deck 218.

[0029] Still looking at FIG. 5, the axle 230 includes a flange 242 and a shaft 240, the subassembly further comprising a bearing 234 or a bushing that defines a outer surface 244 and an inner surface 292 of the bore 232 wherein the outer surface 244 is configured to contact the inner surface 294 of the gear 236 and the inner surface 292 is configured to mate with shaft 240 of the axle 230.

[0030] For the embodiment shown in FIG. 5, two identical roller bearings are provided. Differently configured and/or styled bearings may be provided in other embodiments. In some embodiments, a bushing may be substituted for one or more bearings. Furthermore, the gear 236 is a planetary gear for this embodiment, but may be another type of gear in other embodiments.

[0031] Initially, the assembly process shown by FIG. 5 starts with the shaft 240 of the axle 230 contacting a chamfer of the top bearing 234, guiding the shaft 240 into the bore 232 of the bearing 234. Since an interference fit is usually provided, a pressing operation is typically used to force the shaft 240 of the axle 230 through the first bearing 234 and through the second bearing 234 in like manner until flange 242 of the axle 230 contacts or nearly contacts the chamfered surface 270 of the assembly guide 258.

[0032] Turning to FIG. 6, the use of the assembly guide 258 to align the axle 230 with the upper sleeve 250 can be seen. Initially, the axle 230 is misaligned with the bore 254 of the upper sleeve 250 such that its flange 242 contacts the chamfered surface 270 of the assembly guide 258, as illustrated by the dotted lines 230 in FIG. 6. The chamfered surface 270 directs or funnels the flange 242 of the axle 230 until it is in alignment with the bore 254 of the upper sleeve 250, at which point in time, the flange 242 contacts the cylindrical tube 252 of the upper sleeve 250. The movement of the axle 230 radially is imparted to the bearings 234, 234 through the shaft 240 of the axle 230, causing the bearings 234, 234 and their bores 232, 232 to also align with the bore 254 of the upper sleeve 250.

[0033] As illustrated by FIG. 7, the pressing operation continues until the flange 242 of the axle 230 is fully inserted into the bore 254 of the cylindrical tube 252 of the upper sleeve 250 and the shaft 240 of the axle is fully inserted into the bore 254 of the cylindrical tube 252 of the lower sleeve 250. The pressing operation continues until the flange 242 of the axle 230 presses down on the bearings 234, 234, providing a downward load or force that is exerted on the thrust surface 210 of the flange 284 of the lower sleeve 250 and the lower deck 218 underneath it.

INDUSTRIAL APPLICABILITY

[0034] In practice, an assembly guide as discussed herein may be manufactured, sold or bought to aid in the assembly of a carrier subassembly as described herein. This may be done in a remanufacturing or OEM context, that is to say, the carrier assembly and the assembly guide may be part of an assembly process and an apparatus associated with a new piece of equipment or with repairing or refurbishing an existing piece of equipment.

[0035] FIG. 9 is a flowchart that describes a method for assembling a carrier subassembly for use with a planetary gear train that is compatible with an assembly guide or carrier subassembly as described herein. The method 300 comprises inserting a sleeve having a bore into the bore of a carrier member (step 302), inserting a gear so that the bore of the gear surrounds the bore of the carrier member (step 304), and aligning an assembly guide having a bore by engaging a portion of the assembly guide with an alignment feature of the carrier subassembly such that the bore of the assembly guide is aligned with the bore of the carrier member (step 306).

[0036] Any of the inserting steps may comprise a pressing operation (step 308). The aligning step 306 may include engaging the assembly guide with a portion of the sleeve after the sleeve has been inserted into the bore of the carrier member (step 310). In other embodiments, the aligning step 306 may include engaging a plurality of other bores or other datums of the carrier subassembly so that the bore of the assembly guide is aligned with the bore of the carrier member.

[0037] The method may further comprise inserting an axle into the bore of the assembly guide until the shaft of the axle is concentric with the bore of the gear (step 312). In some embodiments, the sleeve is machined to provide desired dimensions or surfaces (step 314) prior to inserting the axle. For example, the thrust surface or inner bore surface of the sleeve may be machined to provide a desired dimension and/or surface finish, etc. Prior to inserting the sleeve into the carrier member (step 302), the bore and/or thrust surface of the carrier member may be machined to remove worn areas (step 316) prior to inserting the sleeve so that machining the sleeve effectively replaces the dimensions and surface finishes of the carrier member that were present when the carrier member was new.

[0038] When a press fit is desired or needed between the carrier member and a sleeve, a hydraulic cylinder may be inserted between the upper and lower deck of the carrier member so that the hydraulic cylinder may contact either an upper or lower sleeve and the opposite upper or lower deck. The hydraulic cylinder may then be activated until the sleeve is pressed into the carrier member. Alternatively, a draw stud may be inserted through the upper and lower deck and sleeve associated therewith with a nut on one side of the deck and a nut that is then threaded onto the free end of the stud. Tightening the nut opposite of the nut threaded on the free end of the draw stud will cause the draw stud and nut to move away from the interior of the carrier member, pressing onto the sleeve and pressing the sleeve into the carrier member.

[0039] The method may further comprise continuing to insert the axle until its flange contacts the assembly guide (step 324) and continuing to insert the axle until its shaft or flange contacts the sleeve (step 318). A pressing operation may be utilized to exert force on the flange of the sleeve (step 320). At any time after the flange engages a sleeve, the assembly guide may be removed from the carrier subassembly as its function has been satisfied (step 322).

[0040] The materials of any of the components discussed herein, such as the sleeve and assembly guide, may use steel, or any metal or other suitably durable material.

[0041] It will be appreciated that the foregoing description provides examples of the disclosed assembly and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.

[0042] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein.

[0043] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the apparatus and methods of assembly as discussed herein without departing from the scope or spirit of the disclosure(s). Other embodiments of this disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the various embodiments disclosed herein. For example, some of the equipment may be constructed and function differently than what has been described herein and certain steps of any method may be omitted, performed in an order that is different than what has been specifically mentioned or in some cases performed simultaneously or in sub-steps. Furthermore, variations or modifications to certain aspects or features of various embodiments may be made to create further embodiments and features and aspects of various embodiments may be added to or substituted for other features or aspects of other embodiments in order to provide still further embodiments.

[0044] Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.