Application of Sintered Steel for Synchronizer Rings Used in Mechanical Transmissions

Abstract

Synchronizer rings are mechanical components that equalize the gear rotation to be engaged with the sliding sleeve. It is done by the friction property of the synchronizer ring material. Different types of materials are used to manufacture synchronizer rings depending on the application. There are basically two groups of material: dual function, structural and friction properties (Cu-Zn alloys, Al-Si alloys, etc.) and single function, only structural property (rolled and sintered steels, Cu-Zn alloys, Al alloys, etc.). The objective of this work was to propose a solution to the synchronizer ring structural material of a new mechanical transmission design. This component was initially designed with a Cu-Zn alloy and showed premature failure on synchronizer teeth during tests. To eliminate this problem several technical alternatives were analyzed considering the best cost and benefits ratio, defining to use the sintered steel FLC-4908 per MPIF Standard 35.