A combined bearing includes a main body (10) and a mating member (30). The
main body is generally cylindrical, with an axial hole (16) and a cutout
(18) defined therein. The cutout is generally semi-cylindrical and spans
from an outer surface (14) of the main body to the axial hole of the main
body. The mating member has a same configuration as the cutout of the
main body and can be inserted into the cutout to provide a complete
cylinder having the axial hole therein. The main body and the mating
member are made of different materials, one is metal alloy which is
capable of impregnating lubricant oil therein, the other is ceramic
having high hardness. Thus, the combined bearing may combine the
advantages of an oil impregnated bearing and the advantages of a ceramic
bearing.