| 摘要 |
PURPOSE:To stabilize the characteristic without making a device large-sized by a method wherein grooves whose size changes from the side of rotational center toward the outside are formed on at least one of opposed surfaces of a rotary transformer. CONSTITUTION:Coils 29a and 29b are wound around grooves 28a and 28b of the main body of core of the rotary transformer. The surface except for the grooves is covered with non magnetic substance 39, and the shallow grooves 40a is so formed that the outer peripheral side becomes larger than the center side. When current flows into a stator coil 41, resulting in the increase of rotary speed to some degree, the lubricant which fills the space between opposed surfaces of a rotary side core 9 and a fixed side core 10 is fed to the center side under pressure and then generates a high pressure in a thrust direction, and then a dynamic fluid thrust bearing 26S is formed and holds the rotary part by balancing with the force generated by a thrust bearing 17S. Thus, the gap between the opposed surfaces of the rotary transformer can be determined with a good accuracy without making whole the rotary head cylinder large-sized. |
