400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 SAE TECHNICAL PAPER SERIES 1999-01-2792 Development of Long-Life Needle Roller and Cage Assembly with Special Specification and Shaft with Unique Heat Treatment Osamu Kodama and Kaoru Hasegawa KOMATSU Ltd. Norio Fujioka and Katsufumi Abe NTN Corp. International Off-Highway and Powerplant Congress and Exposition Indianapolis, Indiana September 13-15, 1999Downloaded from SAE International by Big Ten Academic Alliance, Tuesday, July 31, 2018The appearance of this ISSN code at the bottom of this page indicates SAE’s consent that copies of the paper may be made for personal or internal use of specific clients. This consent is given on the condition,however, that the copier pay a $7.00 per article copy fee through the Copyright Clearance Center, Inc.Operations Center, 222 Rosewood Drive, Danvers, MA 01923 for copying beyond that permitted by Sec-tions 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such ascopying for general distribution, for advertising or promotional purposes, for creating new collective works,or for resale. SAE routinely stocks printed papers for a period of three years following date of publication. Direct your orders to SAE Customer Sales and Satisfaction Department. Quantity reprint rates can be obtained from the Customer Sales and Satisfaction Department.To request permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact the SAE Publications Group. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior wr itten permission of the publisher. ISSN 0148-7191 Copyright 1999 Society of Automotive Engineers, Inc. Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the paper if it is p ublished in SAE Transactions. For permission to publish this paper in full or in part, contact the SAE Publications Group. Persons wishing to submit papers to be considered for presentation or publication through SAE should send the manuscript or a 3 00 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USAAll SAE papers, standards, and selected books are abstracted and indexed in the Global Mobility DatabaseDownloaded from SAE International by Big Ten Academic Alliance, Tuesday, July 31, 20181 1999-01-2792 Development of Long-Life Needle Roller and Cage Assembly with Special Specification and Shaft with Unique Heat Treatment Osamu Kodama and Kaoru Hasegawa KOMATSU Ltd. Norio Fujioka and Katsufumi Abe NTN Corp. Copyright © 1999 Society of Automotive Engineers, Inc. ABSTRACT A newly developed roller in the needle roller and cage assembly has a special heat treatment and special sur-face modifications. A newly developed shaft, where theouter surface acts as the inner raceway for the rollers,also has an unique heat treatment. The life comparison test results show that the combina- tion of the new rollers and new shaft has an approxi-mately 3.0 times longer life than the conventionalproduct. In the bench test, the new rollers and new shafts are installed in an actual planetary type transmission of aconstruction vehicle. The bench test shows 2.9 timeslonger life. After the bench test, both the new rollers andnew shafts show no sign of damage. INTRODUCTION Fig.1 is an illustration of a planet gear support structure.Between the planet gear and the planet carrier shaft, abearing is usually put so that the planet gear must besupported on the planet carrier shaft as rotationally free.In transmissions of construction vehicles, a needle rollerand cage assembly is used in this portion. To increase the delivered power and to achieve the down- sizing of the tr