Universal joint bearing insert formed from ceramic or composite materials

This invention relates in general to universal joint assemblies for use in vehicular drive train and steering systems. In particular, this invention relates to a universal joint assembly including a cross having at least one trunnion that rotatably supports a bearing cup on the end thereof, wherein a bearing insert formed from a ceramic or composite material is disposed between the trunnion and the bearing cup. A universal joint includes a cross member having a plurality of trunnions extending outwardly therefrom. A hollow bearing cup is disposed about the end of each of the trunnions. Each of the bearing cups has an open end, a closed end, and an inner surface that is disposed about a bearing surface formed on the trunnion. An insert is disposed between the bearing surface of the trunnion and the inner surface of the bearing cup provided thereon. In a first embodiment, an annular groove is formed in the inner surface of the bearing cup that receives the insert therein. In a second embodiment, the insert is disposed between the cylindrical bearing surface of the trunnion and the cylindrical inner surface of the bearing cup. The insert is formed from either a ceramic material or a composite material. The bearing cup may be formed from a metallic material that is molded about the insert.