Текст документа
INDEX
INDEX INTRODUCTION 1 FEATURE OF NEW TRACK 2 STRUCTURE AND FUNCTION OF SEALED & LUBRICATED TRACK 1) TRACK STRUCTURE 3 2) SEAL STRUCTURE AND FUNCTION 4 3) SEAL MECHANISM 5 4) KEY POINT ON BUSHING TURN 6 5) KEY POINT ON SEAL PROTECTION 7 BUSHING TURN PROCEDURE 1) DISASSEMBLY 8 2) REWORK 15 3) ASSEMBLY 19 STANDARD VALUE TABLE 31 PRESS JIG 32 TOOLS 33 TRACK SHOP LAYOUT 39 Application of this Guide This manual, Guidance for Reusable Parts is applicable to the sealed & lubricated track fitted with F3 & F5 type seals.
This Manual was published by the following persons, 1 Structure and Function & Hiroyuki Nakaishi & CETC1 General Techincal information Akira Hashimoto CETC1 2 Bushing turn procedure with photos Hidetoshi Okuno CS Division 3 Acutual bushing turn work coordination Yasu Iiyama NSK
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INTRODUCTION
INTRODUCTION Undercarriage is the most expensive element among several elements of repair and maintenance (hereafter R&M) cost to run a large size bulldozer. And among undercarriage parts such as track , top(carrier) rollers, bottom(track) rollers, idlers, sprocket segments, roller guards and so on, track parts spend major portion of entire undercarriage cost such as 50% or more of the total cost. In order to manage R&M cost in reasonable one, WET TURN OF TRACK BUSHING is the most important issue for large size bulldozer and reduces number of tracks to be replaced with a new one as an example shown in below.
Bulldozer R&M cost Undercarriage R&M cost Other Undercarriage Track Other Track R&M cost No turn Bushing turn In 2001, a new D475A is launched with a new undercarriage system, which is explained in details on the next pages. Wedge rings fitted on both ends of pin assure holding pins and links in proper position even pins are fitted with less force to prevent scuffing. K-bogies prevent from link shoulder chipping by better following-up capability and new guards do not cause inclined wear on pin ends any more. A new F5 seal is adopted and it extends seal life as well.
All these innovations enable WET TURN OF TRACK BUSHING more easily and this manual is issued to introduce the new undercarriage and its WET TURN OF TRACK BUSHING procedure correctly and practically. It would be more effctive if this manual is utilized with separate volume of " Guidance for Reusable Parts - Lubricated Track (II)" Form No. SEBG4091" . We thank very much for all persons of NSK(Australia) who gave us great cooperation on the occasion of taking pictures of actual jobs there for the draft creation. Note: This publication is intended for guidance only and KOMATSU LTD.
hereby expressly denies and excludes any representation, warranty or implied warranty for the reuse of sealed and lubricated track - 1 - Other Other Bushing turn Track2 Track1 Track3 Other Bushing turn Track2 Track2 Track1 Track1
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NEW TRACK STRUCTURE & FEATURE
NEW TRACK STRUCTURE & FEATURE 1) Adoption of wedge ring to the pin hold bore at bushing turn. As a result, man-hour can be shortened and parts reusable ratio can be increased. 2) Link guard and link shape change to avoid interference of pin ends and guards. effect: Pin press-fitting force can be reduced, and it reduce scuffing between pin and link effect: Pin end face wear can be eliminated, then it result man-hour reduction of pin end face maintenance and pin reusable ratio improvement. 3) Expanding of link and rollers tread width effect: Wear life on track link and rollers can be elongated due to surface pressure reduction.
4) Adoption of K-bogie which rollers following-up track link movement. effect: Elimination of track coming off, then rollers flange wear life can be extended. And riding comfort would be improved. - 2 - K- bogie NEW TRACK CURRENT TRACK Track Link tread roller Link Guard Wedge ring
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TRACK STRUCTURE
STRUCTURE OF THE SEALED & LUBRICATED TRACK TRACK STRUCTURE Sealed & lubricated track differs greatly from grease sealed track in the following point. Oil is sealed in the area between pin and bushing (link connection), and special seal is used to prevent entry of soil or water. This greatly improves the elongation life of link pitch. Sealed & lubricated track consists of the links, pins, bushings, seals, spacers, large plugs and small plugs. As for the track that we adopted this time, the following points are changed formerly. 1. The adoption of F5 type seal that improved sealing follow-up ability. 2. The adoption of wedge ring that maintain the pin hold.
F5 seal Bushing Wedge ring Spacer Pin - 3 - Link
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