摘要 |
A rolling bearing (25) and a rod bearing (13) are provided with a tilt mechanism and a rotary mechanism that are mutually independent. The tilt mechanism (A) has a non-lubricated type spherical sliding bearing structure (16,17,17a,27,28,28a). The rotary mechanism (B) has a rolling bearing structure (18,19,20,21,23,29,30,31,32,34) which may or may not be sealed. By means of the non-lubricated type spherical sliding bearing structure, a tilt of the shaft center is made possible, and by means of a sealed rolling bearing structure, problems such as a lubrication oil leak are avoided, and carrying out high speed rotation and continuous rotation become possible. Because the sealed rolling bearing structure of the rotary mechanism does not call for a shaft center tilt function at all, material of the seal can be chosen such that it emphasises sliding resistance and high durability. <IMAGE> |