JSAE 20030172 SAE 2003-01-1969 Initial Wet Clutch Frictional Characteristics of ATF/B-CVTF under Low Speed Sliding Conditions Hisayuki Wada, Toru Matsuoka Nippon Oil Corporation 2003 JSAE/SAE International Spring Fuels & Lubricants Meeting Yokohama, Japan May 19-22, 2003 10-2 Gobancho, Chiodaku, Tokyo 102-0076 Japan Tel:+81-3-3262-8211 Fax:+81-3-3261-2204 Downloaded from SAE International by University of British Columbia, Sunday, July 29, 2018Notice about photocopy In order to photocopy any works from this publication, you or your organization must obtain permission from the following organization which you has been delegated for copyright for clearance by the copyright owner of this publication. Except in the U.S.A. Japan Academic Association for Copyright Clearance (JAACC) 6-41 Akasaka 9-chome, Minato-ku, Tokyo 107-0052 Japan TEL: 81-3-3475-5618 Fax:81-3-3475-5619 E-mail:naka-atsu@ mju.biglobe.ne.jp In the U.S.A. Copyright Clearance Center, Inc. 222 Rosewood Drive, Danvers, MA01923 U.S.A. Phone: 1-978-750-8400 Fax:1-978-750-4744 Copyright © 2003 Society of Automotive Engineers of Japan, Inc. Downloaded from SAE International by University of British Columbia, Sunday, July 29, 2018JSAE 20030172 SAE 2003-01-1969 Initial Wet Clutch Frictional Characteristics of ATF/B-CVTF under Low Speed Sliding Conditions Hisayuki Wada and Toru Matsuoka Nippon Oil Corporation Copyright © 2003 Society of Automotive Engineers of Japan, Inc. ABSTRACT The antishudder performance of automatic transmission fluids (ATFs) and belt-drive continuously variable transmission fluids (B-CVTFs) used in automotive transmissions equipped with slip control torque converter lock-up clutch systems is an important issue. These fluids require both initial antishudder performance and antishudder durability, but most researchers have mainly studied antishudder durability. This paper describes the initial frictional properties—break-in properties—of some commercial ATFs and B-CVTFs using a low velocity friction apparatus (LVFA). INTRODUCTION Automatic transmissions (ATs) are the most common automotive transmissions in Japan. With increased interest in reducing the environmental impact of automobiles, slip control is being adopted for wet clutches. Recently, belt-drive continuously variable transmissions (B-CVTs) have also been adopted together with wet clutches in some automobiles to reduce fuel consumption even more. While the lubricants used in ATs and B-CVTs require antishudder performance, there have been few research reports on the prevention of initial shudder. (1,2) To obtain information about the break-in properties, which are believed to be important for preventing shudder, we examined the relationship between the initial sliding friction characteristics (break-in) and the friction surface roughness of the wet clutch materials. EXPERIMENTAL This experiment was conducted using the low- velocity friction apparatus shown in Fig.1 specified by the antishudder performance test method for ATFs of JASO M349-2001. (3) The friction plates and steel materials used for the wet clutch were also those specified by JASO M349-2001. The test oils were commercial ATF, B-CVTF (A to I in Table 1). Five oils Fig. 1 Low-velocity friction apparatus Table 1 Test oils 1 Downloaded from SAE International by University of British Columbia, Sunday, July 29, 2018of A to E are adopted for ATs. F and G are adopted for not only ATs but also B-CVTs. H and I are adopted for only B-CVTs. The experiment was based on JASO M349-2001, Table 2 Test conditions with the break-in test divided into two stages shown in Table 2. In the first stage (break-in