Analysis of automotive transmission gearbox synchronizer wear due to torsional vibration and the parameters influencing wear reduction. (November 2019)

• Record Type: Journal Article
• Authors: K, Barathiraja; G, Devaradjane; Paul, Jibin; S, Rakesh; Jamadade, Gajanan
• Is Part Of: Engineering failure analysis. Volume 105(2019)
• Page Start: 427
• Page End: 443
• Publication Date: 2019-11
• Subjects: Manual transmission -- Carbon synchronizers -- Wear -- Torsional vibration -- Lubrication -- Angular acceleration; TV Torsional vibration -- GSD Gear shift durability. -- CFD Computational fluid dynamics; System failures (Engineering) -- Periodicals; Fracture mechanics -- Periodicals; Reliability (Engineering) -- Periodicals; Pannes -- Périodiques; Rupture, Mécanique de la -- Périodiques; Fiabilité -- Périodiques; Fracture mechanics; Reliability (Engineering); System failures (Engineering); Periodicals; Electronic journals; 620.112
• DOI: 10.1016/j.engfailanal.2019.06.084
• Languages: English
• ISSNs: 1350-6307

Abstract

Abstract: Synchronizers are the heart for the manual transmission, automated manual transmission and dual clutch transmission. The synchronizers match the speed of the target gears during gear shifts. Downsizing the high-power density engine develops higher angular accelerations. Higher angular accelerations create torsional vibrations and are detrimental to the life of the synchronizers. The synchronizer rings can move freely in the available space due to torsional vibration. The synchronizers which experience higher angular acceleration collide with the surrounding parts and wear out. The wear of synchronizer carbon liner reduces the wear gap to zero. The zero-wear gap hampers the synchronizer functionality and leads to gear clash. This paper presents the impact of angular acceleration on the life of carbon synchronizer ring and the parameters which are influencing to overcome the failure are studied. A bench test set-up was developed to simulate the vehicle level angular accelerations. The bench test results show direct correlation with the life of the synchronizer on the vehicle. Torsional vibration dampening using clutch size, oil viscosity, guiding of synchronizer ring, and oil volume are studied. The synchronizer carbon liner wear reduction is studied and validated with different bench and vehicle level tests. Highlights: Wear of automotive transmission gearbox synchronizer due to torsional vibration is a high threat to the vehicle endurance life. Torsional vibration test rig simulates the vehicle synchronizer wear. The test sequence involved in this study can be used to quickly solve the synchronizer wear problems. The endurance life depends on the clutch size, synchronizer ring clearances, oil grade and oil volume.